Exhibit 99.1

Wintrust Financial Corporation

9700 W. Higgins Road, Suite 800, Rosemont, Illinois 60018

News Release

FOR MORE INFORMATION CONTACT:

Edward J. Wehmer, President & Chief Executive Officer

David A. Dykstra, Senior Executive Vice President & Chief Operating Officer

(847) 939-9000

Web site address: www.wintrust.com

Wintrust Financial Corporation Reports First Quarter 2019 Net Income of $89.1 million ,

An Increase of 9% Over Prior Year Quarter

ROSEMONT, ILLINOIS – Wintrust Financial Corporation (“Wintrust” or “the Company”) (Nasdaq: WTFC) announced net income of $89.1 million or $1.52 per diluted common share for the first quarter of 2019 , an increase in diluted earnings per share of 13% compared to the prior quarter and 9% compared to the first quarter of 2018.

Highlights of the First Quarter of 2019:

    

Edward J. Wehmer, President and Chief Executive Officer, commented, "Wintrust reported net income of $89.1 million for the first quarter of 2019, up from $79.7 million in the fourth quarter of 2018. The Company experienced strong balance sheet growth as total assets were $1.1 billion higher than the prior quarter end and $3.9 billion higher than the first quarter of 2018. The first quarter was characterized by net interest margin expansion, loan and deposit growth, stable credit quality, market volatility impacting the mortgage division and cost control."

Mr. Wehmer continued, "Net interest margin for the Company increased considerably as earning assets benefited from the increase in short term interest rates in late 2018. Additionally, the Company managed deposits costs which continued to moderate as the rate paid on interest bearing deposits increased by nine basis points from the prior quarter or a calculated beta of 36% on the December 2018 rate hike. While this quarter demonstrates the benefit of Wintrust having maintained a rate sensitive position, the Company has taken action in recent quarters to reduce the asset sensitivity of its balance sheet given the recent increase in rates. Given the shape of the interest rate curve and projected interest rate environment, we expect some pressure on net interest

margin in the upcoming quarter. Growing low cost deposits in our market area remains a significant focus of the Company which we believe will be the key in mitigating net interest margin compression."

Mr. Wehmer added, "We experienced strong loan growth in our commercial and commercial premium finance receivables portfolios during the first quarter, increasing our total loans outstanding by $394 million. Our loan pipelines remain consistently strong, and reflect opportunities to continue to grow loans across most of our portfolio segments. Deposits grew by $710 million in the first quarter, lowering our loans to deposits ratio to 90.3% . We expect that we will be able to grow our retail and commercial deposit base while further supplementing deposit growth with deposits generated from the 1031 exchanges facilitated by our Chicago Deferred Exchange Company subsidiary."

Commenting on credit quality, Mr. Wehmer noted, "During the first quarter of 2019, the Company continued its practice of addressing and resolving non-performing credits in a timely fashion. Total non-performing assets increased slightly by $1.0 million during the first quarter, but declined to 0.43% of total assets. Non-performing loans increased by $4.4 million while other real-estate owned declined by $3.3 million during the quarter. Additionally, near-term 60 to 89 day delinquent loans declined to $19.2 million or only 0.1% of total loans in the first quarter of 2019. The allowance for loan losses as a percentage of non-performing loans remained flat to the prior quarter at 135% . As a percentage of average total loans, annualized net charge-offs for the first quarter were nine basis points down from 12 basis points in the prior quarter. We believe that the Company’s reserves remain appropriate and we remain diligent in our review of credit."

Mr. Wehmer further commented, “Our mortgage banking business was impacted by seasonal demand in the first quarter as loan volumes originated for sale decreased to $678.5 million , down from $927.8 million in the fourth quarter of 2018. The decline in origination volume resulted in lower production revenue and a decrease in mortgage servicing rights capitalization revenue. Declining long-term interest rates led to an increase in refinance activity, however home purchase activity continues to make up the majority of our originations accounting for 67% of loan volumes originated for sale in the first quarter. The decrease in long-term mortgage rates resulted in a negative fair value adjustment on our mortgage servicing rights portfolio of $8.7 million related to changes in valuation assumptions as compared to a $7.6 million negative fair value adjustment in the fourth quarter of 2018. These valuation adjustments negatively impacted the net overhead ratio by 11 basis points in the first quarter of 2019 and 10 basis points in the fourth quarter of 2018. We continue to focus on efficiencies in our delivery channels and our operating costs in our mortgage banking area. We believe that the lower mortgage rate outlook bodes well for mortgage origination demand in future quarters."

Turning to the future, Mr. Wehmer stated, “We believe 2019 got off to a strong start as we grew assets significantly while expanding net interest margin, maintaining strong credit quality and managing operating costs. We expect continued organic growth in all areas of our businesses. We will remain diligent in monitoring changes to the interest rate environment and managing the balance sheet to maximize net interest margin and net income. We will continue to take a steady and measured approach to achieving our main objectives of growing franchise value, increasing profitability, leveraging our expense infrastructure and continuing to increase shareholder value. Evaluating strategic acquisitions, like the announced acquisition of Oak Bank, and organic branch growth will also be a part of our overall growth strategy with the continued goal of becoming Chicago’s bank and Wisconsin’s bank. We believe our opportunities for both internal growth and external growth remain consistently strong."

The graphs below illustrate certain highlights of the first quarter of 2019 .

Wintrust’s key operating measures and growth rates for the first quarter of 2019 , as compared to the fourth quarter of 2018 (sequential quarter) and first quarter of 2018 (linked quarter), are shown in the table below:

Certain returns, yields, performance ratios, or quarterly growth rates are “annualized” in this presentation to represent an annual time period. This is done for analytical purposes to better discern for decision-making purposes underlying performance trends when compared to full-year or year-over-year amounts. For example, a 5% growth rate for a quarter would represent an annualized 20% growth rate. Additional supplemental financial information showing quarterly trends can be found on the Company’s website at www.wintrust.com by choosing “Financial Reports” under the “Investor Relations” heading, and then choosing “Financial Highlights.”

Potentially dilutive common shares can result from stock options, restricted stock unit awards, stock warrants, and shares to be issued under the Employee Stock Purchase Plan and the Directors Deferred Fee and Stock Plan, being treated as if they had been either exercised or issued, computed by application of the treasury stock method. While potentially dilutive common shares are typically included in the computation of diluted earnings per share, potentially dilutive common shares are excluded from this computation in periods in which the effect would reduce the loss per share or increase the income per share.

SUPPLEMENTAL FINANCIAL MEASURES/RATIOS

The accounting and reporting policies of Wintrust conform to generally accepted accounting principles (“GAAP”) in the United States and prevailing practices in the banking industry. However, certain non-GAAP performance measures and ratios are used by management to evaluate and measure the Company’s performance. These include taxable-equivalent net interest income (including its individual components), taxable-equivalent net interest margin (including its individual components), the taxable-equivalent efficiency ratio, tangible common equity ratio, tangible book value per common share and return on average tangible common equity. Management believes that these measures and ratios provide users of the Company’s financial information a more meaningful view of the performance of the Company's interest-earning assets and interest-bearing liabilities and of the Company’s operating efficiency. Other financial holding companies may define or calculate these measures and ratios differently.

Management reviews yields on certain asset categories and the net interest margin of the Company and its banking subsidiaries on a fully taxable-equivalent basis. In this non-GAAP presentation, net interest income is adjusted to reflect tax-exempt interest income on an equivalent before-tax basis using tax rates effective as of the end of the period. This measure ensures comparability of net interest income arising from both taxable and tax-exempt sources. Net interest income on a fully taxable-equivalent basis is also used in the calculation of the Company’s efficiency ratio. The efficiency ratio, which is calculated by dividing non-interest expense by total taxable-equivalent net revenue (less securities gains or losses), measures how much it costs to produce one dollar of revenue. Securities gains or losses are excluded from this calculation to better match revenue from daily operations to operational expenses. Management considers the tangible common equity ratio and tangible book value per common share as useful measurements of the Company’s equity. The Company references the return on average tangible common equity as a measurement of profitability.

The following table presents a reconciliation of certain non-GAAP performance measures and ratios used by the Company to evaluate and measure the Company’s performance to the most directly comparable GAAP financial measures for the last five quarters.