Exhibit 99.1

FIRST FINANCIAL BANKSHARES ANNOUNCES

SECOND QUARTER EARNINGS RESULTS

ABILENE, Texas, July 16, 2015 – First Financial Bankshares, Inc. (NASDAQ: FFIN) today reported earnings for the second quarter of 2015 of $25.31 million, up 19.34 percent when compared with earnings of $21.21 million in the same quarter last year. Basic earnings per share were $0.39 for the second quarter of 2015 compared with $0.33 in the same quarter a year ago.

Net interest income for the second quarter of 2015 increased 8.54 percent to $52.34 million compared with $48.22 million in the same period of 2014. The net interest margin, on a taxable equivalent basis, was 4.07 percent compared to 4.11 percent in the first quarter of 2015 and 4.24 percent in the second quarter of 2014. Included in interest income for the second quarter of 2015 was $461 thousand, or four basis points in net interest margin, related to discount accretion from fair value accounting related to the Orange acquisition.

The provision for loan losses was $1.55 million in the second quarter of 2015 compared with $1.29 million in the first quarter of 2015 and $1.12 million in the second quarter of 2014. Nonperforming assets as a percentage of loans and foreclosed assets totaled 0.61 percent at June 30, 2015, compared with 0.69 percent at March 31, 2015, and 0.93 percent at June 30, 2014. Classified loans totaled $95.77 million at June 30, 2015, compared to $77.75 million at March 31, 2015, and $79.93 million at June 30, 2014.

Noninterest income increased 12.20 percent in the second quarter of 2015 to $17.81 million compared with $15.87 million in the same quarter a year ago. Trust fees increased to $4.74 million in the second quarter of 2015 compared with $4.55 million in the same quarter last year, due to continued growth in the fair value of Trust assets managed to $3.97 billion from $3.63 billion a year ago. This growth offset a $264 thousand decline in Trust oil and gas fee income in the second quarter of 2015 compared to the same quarter a year ago. ATM, interchange and credit card fees increased 14.54 percent to $5.45 million compared with $4.75 million in the same quarter last year due to continued growth in net new accounts and debit cards. Real estate mortgage fees increased 45.25 percent in the second quarter of 2015 to $1.94 million compared with $1.34 million in the same quarter a year ago primarily resulting from a stronger mortgage market and the Company’s asset purchase of 4Trust Mortgage, Inc. on May 31, 2015.

Noninterest expense for the second quarter of 2015 totaled $35.20 million compared to $35.00 million in the second quarter of 2014. The Company’s efficiency ratio in the second quarter of 2015 was 46.46 percent compared with 50.84 percent in the same quarter last year. Included in noninterest expense in the second quarter of 2014 was $2.39 million related to a litigation settlement and damages sustained in a hail storm in Abilene. Excluding this amount, noninterest expense for the second quarter of 2015 increased approximately $2.59 million over the same quarter a year ago. The increase in the second quarter of 2015 was primarily a result of an increase in salary and employee benefit costs to $19.17 million compared to $17.27 million in the same period a year ago, primarily driven by the addition of employees to staff new branches and compliance-related areas, the addition of 4Trust Mortgage Inc. employees and annual pay increases.

For the first half of 2015, net income increased 13.23 percent to $49.30 million from $43.54 million a year ago. Basic earnings per share rose to $0.77 in the first half of 2015 from $0.68 in the same period last

year. Net interest income increased 8.43 percent to $103.44 million in the first half of 2015 from $95.39 million in the same period a year ago. The provision for loan losses totaled $2.84 million compared with $2.81 million in the first half of the previous year. Noninterest income was $33.71 million in the first half of 2015 compared with $32.28 million a year ago. Noninterest expense rose to $69.15 million in the first half of 2015 compared with $67.45 million during the same period last year.

As of June 30, 2015, consolidated assets for the Company totaled $6.12 billion compared with $5.45 billion a year ago. Loans grew to $2.97 billion at quarter end compared with loans of $2.79 billion a year ago. Deposits totaled $4.73 billion at June 30, 2015, compared to $4.32 billion a year ago. Shareholders’ equity rose to $701.19 million as of June 30, 2015, compared with $640.04 million in the prior year.

“We are pleased to report another solid quarter for our Company,” said F. Scott Dueser, Chairman, President and CEO. “We continue to see good growth in loans and earnings and continue to find more efficient ways to provide exceptional service to our customers. During the quarter, we completed the asset purchase of 4Trust Mortgage, Inc. and we eagerly anticipate the closing of our acquisition of First Bank, N.A., Conroe, Texas. In light of the current depressed oil and gas prices, we continue to monitor our 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. FFIN recently announced that they have entered into a definitive agreement to acquire FBC Bancshares, Inc. and its wholly-owned subsidiary, First Bank, N.A., Conroe, Texas. Pending final regulatory and shareholder approval, the acquisition is expected to be finalized on July 31, 2015 and would expand First Financial Bankshares’ growing Texas footprint into the cities of Conroe, Magnolia, Montgomery, Cut and Shoot, Willis and The Woodlands, Texas. 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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FIRST FINANCIAL BANKSHARES, INC.

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