* Includes net other assets

See accompanying notes which are an integral part of the financial statements.

 (a) Redemption price per share is equal to net asset value less any applicable contingent deferred sales charge.

See accompanying notes which are an integral part of the financial statements.

See accompanying notes which are an integral part of the financial statements.

See accompanying notes which are an integral part of the financial statements.

Financial Highlights

Fidelity Municipal Income 2021 Fund Class A

 ^A Calculated based on average shares outstanding during the period.

 ^B Amount represents less than $.0005 per share.

 ^C Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

 ^D Total returns do not include the effect of the sales charges.

 ^E Fees and expenses of any underlying Fidelity Central Funds are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of the expenses of any underlying Fidelity Central Funds.

 ^F Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed by the investment adviser or reductions from expense offset arrangements and do not represent the amount paid by the class during periods when reimbursements or reductions occur. Expenses net of fee waivers reflect expenses after reimbursement by the investment adviser but prior to reductions from expense offset arrangements. Expenses net of all reductions represent the net expenses paid by the class.

 ^G Amount does not include the portfolio activity of any underlying Fidelity Central Funds.

See accompanying notes which are an integral part of the financial statements.

 ^A Calculated based on average shares outstanding during the period.

 ^B Amount represents less than $.0005 per share.

 ^C Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

 ^D Fees and expenses of any underlying Fidelity Central Funds are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of the expenses of any underlying Fidelity Central Funds.

 ^E Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed by the investment adviser or reductions from expense offset arrangements and do not represent the amount paid by the class during periods when reimbursements or reductions occur. Expenses net of fee waivers reflect expenses after reimbursement by the investment adviser but prior to reductions from expense offset arrangements. Expenses net of all reductions represent the net expenses paid by the class.

 ^F Amount does not include the portfolio activity of any underlying Fidelity Central Funds.

See accompanying notes which are an integral part of the financial statements.

 ^A Calculated based on average shares outstanding during the period.

 ^B Amount represents less than $.0005 per share.

 ^C Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

 ^D Fees and expenses of any underlying Fidelity Central Funds are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of the expenses of any underlying Fidelity Central Funds.

 ^E Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed by the investment adviser or reductions from expense offset arrangements and do not represent the amount paid by the class during periods when reimbursements or reductions occur. Expenses net of fee waivers reflect expenses after reimbursement by the investment adviser but prior to reductions from expense offset arrangements. Expenses net of all reductions represent the net expenses paid by the class.

 ^F Amount does not include the portfolio activity of any underlying Fidelity Central Funds.

See accompanying notes which are an integral part of the financial statements.

* Includes net other assets

See accompanying notes which are an integral part of the financial statements.

 (a) Redemption price per share is equal to net asset value less any applicable contingent deferred sales charge.

See accompanying notes which are an integral part of the financial statements.

See accompanying notes which are an integral part of the financial statements.

See accompanying notes which are an integral part of the financial statements.

Financial Highlights

Fidelity Municipal Income 2023 Fund Class A

 ^A Calculated based on average shares outstanding during the period.

 ^B Amount represents less than $.0005 per share.

 ^C Total returns for periods of less than one year are not annualized.

 ^D Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

 ^E Total returns do not include the effect of the sales charges.

 ^F Fees and expenses of any underlying Fidelity Central Funds are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of the expenses of any underlying Fidelity Central Funds.

 ^G Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed by the investment adviser or reductions from expense offset arrangements and do not represent the amount paid by the class during periods when reimbursements or reductions occur. Expenses net of fee waivers reflect expenses after reimbursement by the investment adviser but prior to reductions from expense offset arrangements. Expenses net of all reductions represent the net expenses paid by the class.

 ^H Amount does not include the portfolio activity of any underlying Fidelity Central Funds.

See accompanying notes which are an integral part of the financial statements.

 ^A Calculated based on average shares outstanding during the period.

 ^B Amount represents less than $.0005 per share.

 ^C Total returns for periods of less than one year are not annualized.

 ^D Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

 ^E Fees and expenses of any underlying Fidelity Central Funds are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of the expenses of any underlying Fidelity Central Funds.

 ^F Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed by the investment adviser or reductions from expense offset arrangements and do not represent the amount paid by the class during periods when reimbursements or reductions occur. Expenses net of fee waivers reflect expenses after reimbursement by the investment adviser but prior to reductions from expense offset arrangements. Expenses net of all reductions represent the net expenses paid by the class.

 ^G Amount does not include the portfolio activity of any underlying Fidelity Central Funds.

See accompanying notes which are an integral part of the financial statements.

 ^A Calculated based on average shares outstanding during the period.

 ^B Amount represents less than $.0005 per share.

 ^C Total returns for periods of less than one year are not annualized.

 ^D Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

 ^E Fees and expenses of any underlying Fidelity Central Funds are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of the expenses of any underlying Fidelity Central Funds.

 ^F Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed by the investment adviser or reductions from expense offset arrangements and do not represent the amount paid by the class during periods when reimbursements or reductions occur. Expenses net of fee waivers reflect expenses after reimbursement by the investment adviser but prior to reductions from expense offset arrangements. Expenses net of all reductions represent the net expenses paid by the class.

 ^G Amount does not include the portfolio activity of any underlying Fidelity Central Funds.

See accompanying notes which are an integral part of the financial statements.

* Includes net other assets

See accompanying notes which are an integral part of the financial statements.

 (a) Redemption price per share is equal to net asset value less any applicable contingent deferred sales charge.

See accompanying notes which are an integral part of the financial statements.

See accompanying notes which are an integral part of the financial statements.

See accompanying notes which are an integral part of the financial statements.

Financial Highlights

Fidelity Municipal Income 2025 Fund Class A

 ^A For the period May 25, 2017 (commencement of operations) to June 30, 2017.

 ^B Calculated based on average shares outstanding during the period.

 ^C The amount shown for a share outstanding does not correspond with the aggregate net gain (loss) on investments for the period due to the timing of sales and repurchases of shares in relation to fluctuating market values of the investments of the Fund.

 ^D Total returns for periods of less than one year are not annualized.

 ^E Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

 ^F Total returns do not include the effect of the sales charges.

 ^G Fees and expenses of any underlying Fidelity Central Funds are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of the expenses of any underlying Fidelity Central Funds.

 ^H Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed by the investment adviser or reductions from expense offset arrangements and do not represent the amount paid by the class during periods when reimbursements or reductions occur. Expense ratios before reductions for start-up periods may not be representative of longer-term operating periods. Expenses net of fee waivers reflect expenses after reimbursement by the investment adviser but prior to reductions from expense offset arrangements. Expenses net of all reductions represent the net expenses paid by the class.

 ^A For the period May 25, 2017 (commencement of operations) to June 30, 2017.

 ^B Calculated based on average shares outstanding during the period.

 ^C The amount shown for a share outstanding does not correspond with the aggregate net gain (loss) on investments for the period due to the timing of sales and repurchases of shares in relation to fluctuating market values of the investments of the Fund.

 ^D Total returns for periods of less than one year are not annualized.

 ^E Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

 ^F Fees and expenses of any underlying Fidelity Central Funds are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of the expenses of any underlying Fidelity Central Funds.

 ^G Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed by the investment adviser or reductions from expense offset arrangements and do not represent the amount paid by the class during periods when reimbursements or reductions occur. Expense ratios before reductions for start-up periods may not be representative of longer-term operating periods. Expenses net of fee waivers reflect expenses after reimbursement by the investment adviser but prior to reductions from expense offset arrangements. Expenses net of all reductions represent the net expenses paid by the class.

 ^H Annualized

 ^I Amount does not include the portfolio activity of any underlying Fidelity Central Funds.

 ^J Amount not annualized.

See accompanying notes which are an integral part of the financial statements.

 ^A For the period May 25, 2017 (commencement of operations) to June 30, 2017.

 ^B Calculated based on average shares outstanding during the period.

 ^C The amount shown for a share outstanding does not correspond with the aggregate net gain (loss) on investments for the period due to the timing of sales and repurchases of shares in relation to fluctuating market values of the investments of the Fund.

 ^D Total returns for periods of less than one year are not annualized.

 ^E Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

 ^F Fees and expenses of any underlying Fidelity Central Funds are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of the expenses of any underlying Fidelity Central Funds.

 ^G Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed by the investment adviser or reductions from expense offset arrangements and do not represent the amount paid by the class during periods when reimbursements or reductions occur. Expense ratios before reductions for start-up periods may not be representative of longer-term operating periods. Expenses net of fee waivers reflect expenses after reimbursement by the investment adviser but prior to reductions from expense offset arrangements. Expenses net of all reductions represent the net expenses paid by the class.

 ^H Annualized

 ^I Amount does not include the portfolio activity of any underlying Fidelity Central Funds.

 ^J Amount not annualized.

See accompanying notes which are an integral part of the financial statements.

Notes to Financial Statements

For the period ended June 30, 2020

1. Organization.

Fidelity Municipal Income 2021 Fund, Fidelity Municipal Income 2023 Fund and Fidelity Municipal Income 2025 Fund (the Funds) are funds of Fidelity Salem Street Trust (the Trust) and are authorized to issue an unlimited number of shares. The Trust is registered under the Investment Company Act of 1940, as amended (the 1940 Act), as an open-end management investment company organized as a Massachusetts business trust. Fidelity Municipal Income 2025 Fund is a non-diversified fund. The Funds offer Class A, Class I, and Retail Class shares, each of which has equal rights as to assets and voting privileges. Each class has exclusive voting rights with respect to matters that affect that class. Effective after the close of business on June 30, 2020, the Fidelity Municipal Income 2021 Fund was closed to new accounts with certain exceptions.

Effective January 1, 2020:

Investment advisers Fidelity Investments Money Management, Inc., FMR Co., Inc., and Fidelity SelectCo, LLC, merged with and into Fidelity Management & Research Company. In connection with the merger transactions, the resulting, merged investment adviser was then redomiciled from Massachusetts to Delaware, changed its corporate structure from a corporation to a limited liability company, and changed its name to "Fidelity Management & Research Company LLC".

Broker-dealer Fidelity Distributors Corporation merged with and into Fidelity Investments Institutional Services Company, Inc. ("FIISC"). FIISC was then redomiciled from Massachusetts to Delaware, changed its corporate structure from a corporation to a limited liability company, and changed its name to "Fidelity Distributors Company LLC".

Fidelity Investments Institutional Operations Company, Inc. converted from a Massachusetts corporation to a Massachusetts LLC, and changed its name to "Fidelity Investments Institutional Operations Company LLC".

2. Investments in Fidelity Central Funds.

The Funds invest in Fidelity Central Funds, which are open-end investment companies generally available only to other investment companies and accounts managed by the investment adviser and its affiliates. The Funds' Schedules of Investments list each of the Fidelity Central Funds held as of period end, if any, as an investment of each Fund, but do not include the underlying holdings of each Fidelity Central Fund. As an Investing Fund, each Fund indirectly bears its proportionate share of the expenses of the underlying Fidelity Central Funds.

The Money Market Central Funds seek preservation of capital and current income and are managed by the investment adviser. Annualized expenses of the Money Market Central Funds as of their most recent shareholder report date ranged from less than .005% to .01%.

A complete unaudited list of holdings for each Fidelity Central Fund is available upon request or at the Securities and Exchange Commission (the SEC) website at www.sec.gov. In addition, the financial statements of the Fidelity Central Funds, which are not covered by the Funds' Report of Independent Registered Public Accounting Firm, are available on the SEC website or upon request.

3. Significant Accounting Policies.

Each Fund is an investment company and applies the accounting and reporting guidance of the Financial Accounting Standards Board (FASB) Accounting Standards Codification Topic 946 Financial Services – Investments Companies. The financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP), which require management to make certain estimates and assumptions at the date of the financial statements. Actual results could differ from those estimates. Subsequent events, if any, through the date that the financial statements were issued have been evaluated in the preparation of the financial statements. The following summarizes the significant accounting policies of the Funds:

Investment Valuation. Investments are valued as of 4:00 p.m. Eastern time on the last calendar day of the period. The Board of Trustees (the Board) has delegated the day to day responsibility for the valuation of each Fund's investments to the Fair Value Committee (the Committee) established by each Fund's investment adviser. In accordance with valuation policies and procedures approved by the Board, each Fund attempts to obtain prices from one or more third party pricing vendors or brokers to value its investments. When current market prices, quotations or currency exchange rates are not readily available or reliable, investments will be fair valued in good faith by the Committee, in accordance with procedures adopted by the Board. Factors used in determining fair value vary by investment type and may include market or investment specific events, changes in interest rates and credit quality. The frequency with which these procedures are used cannot be predicted and they may be utilized to a significant extent. The Committee oversees each Fund's valuation policies and procedures and reports to the Board on the Committee's activities and fair value determinations. The Board monitors the appropriateness of the procedures used in valuing each Fund's investments and ratifies the fair value determinations of the Committee.

Each Fund categorizes the inputs to valuation techniques used to value its investments into a disclosure hierarchy consisting of three levels as shown below:

• Level 1 – quoted prices in active markets for identical investments
• Level 2 – other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, etc.)
• Level 3 – unobservable inputs (including the Fund's own assumptions based on the best information available)

Valuation techniques used to value each Fund's investments by major category are as follows:

Debt securities, including restricted securities, are valued based on evaluated prices received from third party pricing vendors or from brokers who make markets in such securities. Municipal securities are valued by pricing vendors who utilize matrix pricing which considers yield or price of bonds of comparable quality, coupon, maturity and type or by broker-supplied prices. When independent prices are unavailable or unreliable, debt securities may be valued utilizing pricing methodologies which consider similar factors that would be used by third party pricing vendors. Debt securities are generally categorized as Level 2 in the hierarchy but may be Level 3 depending on the circumstances.

Investments in open-end mutual funds, including the Fidelity Central Funds, are valued at their closing net asset value (NAV) each business day and are categorized as Level 1 in the hierarchy.

Changes in valuation techniques may result in transfers in or out of an assigned level within the disclosure hierarchy. The aggregate value of investments by input level as of June 30, 2020 is included at the end of each Fund's Schedule of Investments.

Investment Transactions and Income. For financial reporting purposes, the Funds' investment holdings and NAV include trades executed through the end of the last business day of the period. The NAV per share for processing shareholder transactions is calculated as of the close of business of the New York Stock Exchange (NYSE), normally 4:00 p.m. Eastern time and includes trades executed through the end of the prior business day. Gains and losses on securities sold are determined on the basis of identified cost. Income and capital gain distributions from Fidelity Central Funds, if any, are recorded on the ex-dividend date. Interest income is accrued as earned and includes coupon interest and amortization of premium and accretion of discount on debt securities as applicable. Debt obligations may be placed on non-accrual status and related interest income may be reduced by ceasing current accruals and writing off interest receivables when the collection of all or a portion of interest has become doubtful based on consistently applied procedures. A debt obligation is removed from non-accrual status when the issuer resumes interest payments or when collectability of interest is reasonably assured.

Class Allocations and Expenses. Investment income, realized and unrealized capital gains and losses, common expenses of each Fund, and certain fund-level expense reductions, if any, are allocated daily on a pro-rata basis to each class based on the relative net assets of each class to the total net assets of each Fund. Each class differs with respect to transfer agent and distribution and service plan fees incurred. Certain expense reductions may also differ by class. For the reporting period, the allocated portion of income and expenses to each class as a percent of its average net assets may vary due to the timing of recording these transactions in relation to fluctuating net assets of the classes. Expenses directly attributable to a fund are charged to that fund. Expenses attributable to more than one fund are allocated among the respective funds on the basis of relative net assets or other appropriate methods. Expense estimates are accrued in the period to which they relate and adjustments are made when actual amounts are known.

Income Tax Information and Distributions to Shareholders. Each year, each Fund intends to qualify as a regulated investment company under Subchapter M of the Internal Revenue Code, including distributing substantially all of its taxable income and realized gains. As a result, no provision for U.S. Federal income taxes is required. As of June 30, 2020, each Fund did not have any unrecognized tax benefits in the financial statements; nor is each Fund aware of any tax positions for which it is reasonably possible that the total amounts of unrecognized tax benefits will significantly change in the next twelve months. Each Fund files a U.S. federal tax return, in addition to state and local tax returns as required. Each Fund's federal income tax returns are subject to examination by the Internal Revenue Service (IRS) for a period of three fiscal years after they are filed. State and local tax returns may be subject to examination for an additional fiscal year depending on the jurisdiction.

Distributions are declared and recorded daily and paid monthly from net investment income. Distributions from realized gains, if any, are declared and recorded on the ex-dividend date. Income and capital gain distributions are declared separately for each class. Income and capital gain distributions are determined in accordance with income tax regulations, which may differ from GAAP. In addition, certain Funds claimed a portion of the payment made to redeeming shareholders as a distribution for income tax purposes.

Capital accounts within the financial statements are adjusted for permanent book-tax differences. These adjustments have no impact on net assets or the results of operations. Capital accounts are not adjusted for temporary book-tax differences which will reverse in a subsequent period.

Book-tax differences are primarily due to market discount and capital loss carryforwards.

The Funds purchase municipal securities whose interest, in the opinion of the issuer, is free from federal income tax. There is no assurance that the IRS will agree with this opinion. In the event the IRS determines that the issuer does not comply with relevant tax requirements, interest payments from a security could become federally taxable, possibly retroactively to the date the security was issued.

As of period end, the cost and unrealized appreciation (depreciation) in securities, and derivatives if applicable, for federal income tax purposes were as follows for each Fund:

The tax-based components of distributable earnings as of period end were as follows for each Fund:

Capital loss carryforwards are only available to offset future capital gains of the Funds to the extent provided by regulations and may be limited. The capital loss carryforward information presented below, including any applicable limitation, is estimated as of fiscal period end and is subject to adjustment.

The tax character of distributions paid was as follows:

Delayed Delivery Transactions and When-Issued Securities. During the period, certain Funds transacted in securities on a delayed delivery or when-issued basis. Payment and delivery may take place after the customary settlement period for that security. The price of the underlying securities and the date when the securities will be delivered and paid for are fixed at the time the transaction is negotiated. The securities purchased on a delayed delivery or when-issued basis are identified as such in each applicable Fund's Schedule of Investments. Certain Funds may receive compensation for interest forgone in the purchase of a delayed delivery or when-issued security. With respect to purchase commitments, each applicable Fund identifies securities as segregated in its records with a value at least equal to the amount of the commitment. Losses may arise due to changes in the value of the underlying securities or if the counterparty does not perform under the contract's terms, or if the issuer does not issue the securities due to political, economic, or other factors.

4. Purchases and Sales of Investments.

Purchases and sales of securities, other than short-term securities, are noted in the table below.

5. Fees and Other Transactions with Affiliates.

Management Fee. Fidelity Management & Research Company LLC (the investment adviser) and its affiliates provide the Funds with investment management related services for which the Funds pay a monthly management fee that is based on an annual rate of .30% of average net assets. Under the management contract, the investment adviser pays all other fund-level expenses, except the compensation of the independent Trustees and certain other expenses such as interest expense, including commitment fees.

Distribution and Service Plan Fees. In accordance with Rule 12b-1 of the 1940 Act, each Fund has adopted separate Distribution and Service Plans for each class of shares. Each Fund's Class A pays Fidelity Distributors Company (FDC), an affiliate of the investment adviser, a Service Fee based on an annual percentage of Class A's average net assets. In addition, FDC may pay financial intermediaries for selling shares of the Funds and providing shareholder support services. For the period, the Service Fee rate, total service fees and amounts retained by FDC were as follows:

Sales Load. FDC may receive a front-end sales charge of up to 2.75% for selling each Fund's Class A shares, some of which is paid to financial intermediaries for selling shares of the Fund. Depending on the holding period, FDC may receive contingent deferred sales charges levied on Class A redemptions. The deferred sales charge is .75% or .50% for certain purchases of each Fund's Class A shares.

For the period, sales charge amounts retained by FDC were as follows:

Transfer Agent Fees. Fidelity Investments Institutional Operations Company LLC (FIIOC), an affiliate of the investment adviser, is the transfer, dividend disbursing and shareholder servicing agent for the Funds. FIIOC receives asset-based fees of .10% of class-level average net assets for each class of each Fund. FIIOC pays for typesetting, printing and mailing of shareholder reports, except proxy statements. For the period, transfer agent fees for each class of each fund were as follows:

Interfund Trades. Funds may purchase from or sell securities to other Fidelity Funds under procedures adopted by the Board. The procedures have been designed to ensure these interfund trades are executed in accordance with Rule 17a-7 of the 1940 Act. Interfund trades are included within the respective purchases and sales amounts shown in the Purchases and Sales of Investments note.

6. Committed Line of Credit.

Certain Funds participate with other funds managed by the investment adviser or an affiliate in a $4.25 billion credit facility (the "line of credit") to be utilized for temporary or emergency purposes to fund shareholder redemptions or for other short-term liquidity purposes. The participating funds have agreed to pay commitment fees on their pro-rata portion of the line of credit, which are reflected in Commitment fees on the Statement of Operations, and are as follows:

During the period, there were no borrowings on this line of credit.

7. Expense Reductions.

Through arrangements with each applicable Fund's custodian, credits realized as a result of certain uninvested cash balances were used to reduce each applicable Fund's or class' expenses. All of the applicable expense reductions are noted in the table below.

8. Distributions to Shareholders.

Distributions to shareholders of each class were as follows:

9. Share Transactions.

Share transactions for each class were as follows and may contain automatic conversions between classes or exchanges between affiliated funds:

10. Other.

The Funds' organizational documents provide former and current trustees and officers with a limited indemnification against liabilities arising in connection with the performance of their duties to the Funds. In the normal course of business, the Funds may also enter into contracts that provide general indemnifications. The Funds' maximum exposure under these arrangements is unknown as this would be dependent on future claims that may be made against the Funds. The risk of material loss from such claims is considered remote.

At the end of the period, the investment adviser or its affiliates were owners of record of more than 10% of the outstanding shares of the following funds:

11. Coronavirus (COVID-19) Pandemic.

An outbreak of COVID-19 first detected in China during December 2019 has since spread globally and was declared a pandemic by the World Health Organization during March 2020. Developments that disrupt global economies and financial markets, such as the COVID-19 pandemic, may magnify factors that affect the Funds' performance.

Report of Independent Registered Public Accounting Firm

To the Board of Trustees of Fidelity Salem Street Trust and Shareholders of Fidelity Municipal Income 2021 Fund, Fidelity Municipal Income 2023 Fund and Fidelity Municipal Income 2025 Fund:

Opinion on the Financial Statements and Financial Highlights

We have audited the accompanying statements of assets and liabilities of Fidelity Municipal Income 2021 Fund, Fidelity Municipal Income 2023 Fund and Fidelity Municipal Income 2025 Fund (the "Funds"), each a fund of Fidelity Salem Street Trust, including the schedules of investments, as of June 30, 2020, the related statements of operations for the year then ended, the statements of changes in net assets for each of the two years in the period then ended, the financial highlights for each of the five years in the period then ended for the Funds, except Fidelity Municipal Income 2025 Fund; the related statements of operations for the year then ended, the statements of changes in net assets for each of the two years in the period then ended, the financial highlights for each of the three years in the period then ended and for the period from May 25, 2017 (commencement of operations) to June 30, 2017, for Fidelity Municipal Income 2025 Fund; and the related notes. In our opinion, the financial statements and financial highlights present fairly, in all material respects, the financial position of each of the Funds as of June 30, 2020, and the results of their operations for the year then ended, the changes in their net assets for each of the two years in the period then ended, and the financial highlights for each of the five years in the period then ended (or for the period mentioned above), in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

These financial statements and financial highlights are the responsibility of the Funds’ management. Our responsibility is to express an opinion on the Funds’ financial statements and financial highlights based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Funds in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements and financial highlights are free of material misstatement, whether due to error or fraud. The Funds are not required to have, nor were we engaged to perform, an audit of their internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Funds’ internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the financial statements and financial highlights, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements and financial highlights. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements and financial highlights. Our procedures included confirmation of securities owned as of June 30, 2020, by correspondence with the custodian and brokers; when replies were not received from brokers, we performed other auditing procedures. We believe that our audits provide a reasonable basis for our opinion.

/s/ Deloitte & Touche LLP

Boston, Massachusetts

August 11, 2020

We have served as the auditor of one or more of the Fidelity investment companies since 1999.