Exhibit 99.1

FIRST FINANCIAL BANKSHARES ANNOUNCES FOURTH QUARTER EARNINGS RESULTS AND 32^nd YEAR OF CONSECUTIVE EARNINGS GROWTH

ABILENE, Texas, January 24, 2019 – First Financial Bankshares, Inc. (NASDAQ: FFIN) today reported earnings for the fourth quarter of 2018 of $38.44 million, up $2.29 million when compared with earnings of $36.14 million in the same quarter last year. Basic earnings per share were $0.57 for the fourth quarter of 2018 compared with $0.55 in the same quarter a year ago. Included in noninterest expense in the fourth quarter of 2018 was $1.55 million, before income tax, resulting from the Company’s partial settlement of its frozen defined benefit pension plan (see below for more details). Additionally, the Company recorded a $322 thousand prior year income tax benefit in the fourth quarter of 2018 resulting from refinements in the re-measurement of its deferred tax balance related to the Tax Cuts and Jobs Act which lowered the Company’s corporate income tax rate to 21% from 35% at the end of 2017.

All amounts for the three months and year ended December 31, 2018, include the results of the Company’s acquisition of Commercial Bancshares, Inc. and its wholly-owned subsidiary, Commercial State Bank, Kingwood, Texas, which was effective January 1, 2018. As of the acquisition date, Commercial State Bank had total assets of approximately $390.20 million, total loans of approximately $271.50 million and total deposits of approximately $345.90 million.

Net interest income for the fourth quarter of 2018 was $70.27 million compared with $60.89 million in the same quarter of 2017. The net interest margin, on a taxable equivalent basis, was 4.02 percent for the fourth quarter of 2018 compared to 4.01 percent in the third quarter of 2018 and 4.00 percent in the fourth quarter of 2017. Included in interest income for the fourth quarter of 2018 was $491 thousand, or three basis points in net interest margin, related to discount accretion from fair value accounting related to the Kingwood and Orange acquisitions.

The provision for loan losses was $1.80 million in the fourth quarter of 2018 compared with $1.45 million in the third quarter of 2018 and $1.44 million in the fourth quarter of 2017. Nonperforming assets as a percentage of loans and foreclosed assets totaled 0.75 percent at December 31, 2018, compared with 0.69 percent at September 30, 2018, and 0.57 percent at December 31, 2017. Classified loans totaled $126.30 million at December 31, 2018, compared to $117.52 million at September 30, 2018, and $117.21 million at December 31, 2017.

Noninterest income increased 11.19 percent in the fourth quarter of 2018 to $24.80 million compared with $22.30 million in the same quarter a year ago. Trust fees increased $1.02 million to $6.92 million in the fourth quarter of 2018 compared with $5.89 million in the same quarter last year, primarily due to continued growth in the fair value of Trust assets managed to $5.60 billion from $5.13 billion a year ago. ATM, interchange and credit card fees increased 5.74 percent to $6.96 million compared with $6.58 million in the same quarter last year due to continued growth in debit cards and the Kingwood acquisition. Service charges on deposits increased 16.59 percent to $5.71 million compared with $4.90 million in the same quarter a year

ago, primarily due to continued growth in net new accounts, product and pricing changes made to better align the Company’s account offerings and the Kingwood acquisition.

Noninterest expense for the fourth quarter of 2018 totaled $48.24 million compared to $44.10 million in the fourth quarter of 2017. The Company’s efficiency ratio in the fourth quarter of 2018 was 49.69 percent compared with 49.37 percent in the same quarter last year. During the fourth quarter of 2018, the Company settled the portion of its pension obligation for plan participants no longer employed by the Company that are in payout. As a result of the partial settlement of the plan, the Company recognized $1.55 million, before income tax, in settlement loss, a component of noninterest expense. Also included in noninterest expense in the fourth quarter of 2018 was a $1.33 million increase in salary and employee benefit costs to $25.75 million compared to $24.42 the same quarter a year ago, primarily driven by the Kingwood acquisition, annual merit based pay increases and an increase in profit sharing expenses.

For the year ended December 31, 2018, net income increased $30.27 million to $150.64 million from $120.37 million in 2017, marking 2018 as the 32^nd consecutive year of earnings increases for the Company. Basic earnings per share in 2018 rose to $2.23 from $1.82 in the previous year. Net interest income increased $36.07 million for the year to $272.76 million from $236.69 million a year ago. The provision for loan losses for 2018 totaled $5.67 million compared with $6.53 million in 2017. Noninterest income was $101.76 million in 2018 compared with $91.02 million in 2017. Noninterest expense rose to $190.68 million in 2018 compared with $173.99 million a year ago.

As of December 31, 2018, consolidated assets for the Company totaled $7.73 billion compared with $7.25 billion at December 31, 2017. Loans totaled $3.98 billion at year end compared with loans of $3.50 billion a year ago. Deposits totaled $6.18 billion at December 31, 2018, compared to $5.96 billion a year ago. Shareholders’ equity rose to $1.05 billion at year end compared with $922.77 million at December 31, 2017.

“We are pleased to report the 32^nd consecutive year of increased earnings for the Company, which does not just happen. It comes from the hard work and dedication of our board, officers and employees,” said F. Scott Dueser, Chairman, President and CEO. “We continue to work diligently to grow loans and deposits, reduce expenses to improve our bottom line while continuing to look for acquisition opportunities to better utilize our strong capital position and increase our return to our shareholders. In light of the continued increases in interest rates by the Federal Reserve, we continue to focus on increasing loan and deposit rates to better align with our competitive environment,” added Dueser.

About First Financial Bankshares

Headquartered in Abilene, Texas, First Financial Bankshares, Inc. is a financial holding company that through its subsidiary, First Financial Bank, N.A., operates multiple banking regions with 73 locations in Texas, including Abilene, Acton, Albany, Aledo, Alvarado, Beaumont, Boyd, Bridgeport, Brock, Burleson, Cisco, Cleburne, Clyde, Conroe, Cut and Shoot, Decatur, Eastland, El Campo, Fort Worth, Fulshear, Glen Rose, Granbury, Grapevine, Hereford, Huntsville, Keller, Kingwood, Magnolia, Mauriceville, Merkel, Midlothian, Mineral Wells, Montgomery, Moran,

New Waverly, Newton, Odessa, Orange, Palacios, Port Arthur, Ranger, Rising Star, Roby, San Angelo, Southlake, Spring, Stephenville, Sweetwater, Tomball, Trent, Trophy Club, Vidor, Waxahachie, Weatherford, Willis, and Willow Park. The Company also operates First Financial Trust & Asset Management Company, N.A., with eight locations and First Technology Services, Inc., a technology operating company.

The Company is listed on The NASDAQ Global Select Market under the trading symbol FFIN. For more information about First Financial Bankshares, please visit our website at http://www.ffin.com.

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Certain statements contained herein may be considered “forward-looking statements” as defined in the Private Securities Litigation Reform Act of 1995. These statements are based upon the belief of the Company’s management, as well as assumptions made beyond information currently available to the Company’s management, and may be, but not necessarily are, identified by such words as “expect”, “plan”, “anticipate”, “target”, “forecast” and “goal”. Because such “forward-looking statements” are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Factors that could cause actual results to differ materially from the Company’s expectations include competition from other financial institutions and financial holding companies; the effects of and changes in trade, monetary and fiscal policies and laws, including interest rate policies of the Federal Reserve Board; changes in the demand for loans; fluctuations in value of collateral and loan reserves; inflation, interest rate, market and monetary fluctuations; changes in consumer spending, borrowing and savings habits; and acquisitions and integration of acquired businesses, and similar variables.    Other key risks are described in the Company’s reports filed with the Securities and Exchange Commission, which may be obtained under “Investor Relations-Documents/Filings” on the Company’s Web site or by writing or calling the Company at 325.627.7155. Except as otherwise stated in this news announcement, the Company does not undertake any obligation to update publicly or revise any forward-looking statements because of new information, future events or otherwise.

FIRST FINANCIAL BANKSHARES, INC.

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