EXHIBIT 99.1

FIRST FINANCIAL BANKSHARES ANNOUNCES FIRST QUARTER EARNINGS RESULTS

ABILENE, Texas, April 16, 2015 – First Financial Bankshares, Inc. (NASDAQ: FFIN) today reported earnings for the first quarter of 2015 of $24.00 million, up 7.44 percent when compared with earnings of $22.34 million in the same quarter last year. Basic earnings per share were $0.37 for the first quarter of 2015 compared with $0.35 in the same quarter a year ago.

Net interest income for the first quarter of 2015 increased 8.32 percent to $51.10 million compared with $47.17 million in the same period of 2014. The net interest margin, on a taxable equivalent basis, was 4.11 percent compared to 4.08 percent in the fourth quarter of 2014 and 4.32 percent in the first quarter of 2014. Included in interest income for the first quarter of 2015 was $489 thousand, or three basis points in net interest margin, related to discount accretion from fair value accounting related to the Orange and Huntsville acquisitions.

The provision for loan losses was $1.29 million in the first quarter of 2015 compared with $755 thousand in the fourth quarter of 2014 and $1.69 million in the first quarter of 2014. Nonperforming assets as a percentage of loans and foreclosed assets totaled 0.69 percent at March 31, 2015, compared with 0.74 percent at December 31, 2014, and 1.02 percent at March 31, 2014. Classified loans totaled $77.75 million at March 31, 2015, compared to $72.98 million at December 31, 2014, and $81.56 million at March 31, 2014.

Noninterest income decreased 3.10 percent in the first quarter of 2015 to $15.90 million compared with $16.41 million in the same quarter a year ago. Included in noninterest income in the first quarter of 2014 was a $605 thousand gain from the settlement of a bank owned life insurance contract and a gain on sale of foreclosed assets of $452 thousand compared to only $30 thousand in the first quarter of 2015. Trust fees increased to $4.73 million in the first quarter of 2015 compared with $4.58 million in the same quarter last year, due to continued growth in the fair value of Trust assets managed to $3.85 billion from $3.47 billion a year ago. This growth offset a $241 thousand decline in Trust oil and gas fee income in the first quarter of 2015 compared to the same quarter a year ago. ATM, interchange and credit card fees increased 11.84 percent to $4.97 million compared with $4.44 million in the same quarter last year due to continued growth in net new accounts and debit cards. Real estate mortgage fees increased 39.36 percent in the first quarter of 2015 to $1.43 million compared with $1.02 million in the same quarter a year ago.

Noninterest expense for the first quarter of 2015 totaled $33.94 million compared to $32.45 million in the first quarter of 2014. The Company’s efficiency ratio in the first quarter of 2015 was 47.01 percent compared with 47.57 percent in the same quarter last year. The increase in noninterest expense in the first quarter of 2015 was primarily a result of an increase in salary and employee benefit costs to $18.27 million compared to $17.41 million in the same year ago, primarily driven by the addition of employees to staff new branches, compliance-related areas and annual pay increases.

As of March 31, 2015, consolidated assets for the Company totaled $6.03 billion compared with $5.28 billion a year ago. Loans totaled $2.94 billion at quarter end compared with loans of $2.70 billion a year

ago. Total deposits grew 14.23 percent to $4.84 billion at March 31, 2015, compared to $4.23 billion a year ago. Shareholders’ equity rose to $706.25 million as of March 31, 2015, compared with $616.57 million in the prior year.

“We are pleased to report another successful quarter for our company and continue to work to grow and improve our efficiencies,” said F. Scott Dueser, Chairman, President and CEO. “We are very excited about the additions of our newest proposed acquisition, First Bank, N.A., Conroe, Texas, and the asset purchase agreement of 4Trust Mortgage, Inc. We believe these additions to the First Financial family fit well into our footprint and continues our strategy to buy well-run banks and companies in high growth areas, which bring good earnings opportunities. In light of the current depressed oil and gas prices, we continue to monitor our direct exposure to the oil and gas industry, which has remained at approximately 3%, consistent with the 2014 year-end balances.”

About First Financial Bankshares

Headquartered in Abilene, Texas, First Financial Bankshares is a financial holding company that operates 12 banking regions with 62 locations in Texas including Abilene, Acton, Albany, Aledo, Alvarado, Beaumont, Boyd, Bridgeport, Brock, Burleson, Cisco, Cleburne, Clyde, Decatur, Eastland, Fort Worth, Glen Rose, Granbury, Grapevine, Hereford, Huntsville, Keller, Mauriceville, Merkel, Midlothian, Mineral Wells, Moran, New Waverly, Newton, Odessa, Orange, Port Arthur, Ranger, Rising Star, Roby, San Angelo, Southlake, Stephenville, Sweetwater, Trent, Trophy Club, Vidor, Waxahachie, Weatherford 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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