Exhibit 99.1

FIRST FINANCIAL BANKSHARES ANNOUNCES

THIRD QUARTER EARNINGS RESULTS

ABILENE, Texas, October 20, 2016 – First Financial Bankshares, Inc. (NASDAQ: FFIN) today reported earnings for the third quarter of 2016 of $25.60 million compared with earnings of $25.89 million in the same quarter last year. Basic earnings per share were $0.39 for the third quarter of 2016 compared with $0.40 in the same quarter a year ago.

All amounts for the third quarter and nine months ended September 30, 2016, include the results of the asset purchase of 4Trust Mortgage, Inc. on May 31, 2015, and the acquisition of First Bank, N.A., Conroe, Texas, on July 31, 2015. As of the acquisition date, First Bank had total gross loans of $252.46 million and total deposits of $356.75 million.

Net interest income for the third quarter of 2016 increased 1.12 percent to $56.73 million compared with $56.10 million in the same quarter of 2015. The net interest margin, on a taxable equivalent basis, was 4.04 percent for the third quarter of 2016 compared to 4.12 percent for the second quarter of 2016 and 4.13 percent for the third quarter of 2015. Included in interest income for the third quarter of 2016 was $528 thousand, or four basis points in net interest margin, related to discount accretion from fair value accounting related to the Conroe and Orange acquisitions.

The provision for loan losses was $3.83 million in the third quarter of 2016 compared with $2.06 million in the second quarter of 2016 and $2.66 million in the third quarter of 2015. The continued provision for loan losses in 2016 reflects the continued levels of nonperforming and classified assets, gross charge-offs, as well as the economic effects related to the oil and gas industry. Nonperforming assets as a percentage of loans and foreclosed assets totaled 1.04 percent at September 30, 2016, compared with 1.22 percent at June 30, 2016, and 0.69 percent at September 30, 2015. Classified loans totaled $126.60 million at September 30, 2016, compared to $132.67 million at June 30, 2016, and $112.12 million at September 30, 2015. The increase in provision for loan losses and gross charge-offs in the third quarter of 2016, when compared to the second quarter of 2016 and the same quarter a year ago, is primarily related to one nonaccrual commercial loan, which is in the process of liquidation. The Company recorded gross charge-offs totaling $3.0 million in the third quarter of 2016 due to new facts and circumstances related to this loan. The Company has recorded $4.0 million for the nine months ended September 30, 2016, on this loan.

At September 30, 2016, loans with oil and gas industry exposure totaled 2.58% of gross loans. These loans comprised $31.54 million of the classified loan totals and $5.14 million of the nonperforming loan totals. In addition, $104 thousand in net charge-offs was related to these oil and gas loans for the quarter ended September 30, 2016. At September 30, 2016, the Company’s allowance for loan loss reserve specific to its total oil and gas loan portfolio totaled 5.60% of total oil and gas loans.

Noninterest income increased 8.34 percent in the third quarter of 2016 to $22.15 million compared with $20.45 million in the same quarter a year ago. Trust fees increased to $5.07 million in the third quarter of 2016 compared with $4.82 million in the same quarter last year, due to continued growth in the fair value of Trust assets managed to $4.22 billion from $3.83 billion a year ago. This growth offset a $76 thousand decline in Trust oil and gas fee income in the third quarter of 2016 compared to the same quarter a year ago. ATM, interchange and credit card fees and service charges on deposit accounts increased 3.56 percent and 3.07 percent, respectively, to $6.00 million and $4.80 million compared with $5.79 million and $4.65 million, respectively, in the same quarter last year due to continued growth in net new accounts and debit cards. Real estate mortgage fees increased 25.52 percent in the third quarter of 2016 to $4.70 million compared with $3.74 million in the same quarter a year ago.

Noninterest expense for the third quarter of 2016 totaled $42.00 million compared to $39.97 million in the third quarter of 2015. The Company’s efficiency ratio in the third quarter of 2016 was 49.33 percent compared with 48.44 percent in the same quarter last year. The increase in noninterest expense in the third quarter of 2016 was primarily a result of an increase in salary and employee benefit costs to $22.93 million compared to $21.65 million in the same quarter a year ago, primarily driven by the addition of 4Trust Mortgage and First Bank employees, annual pay increases and a significant increase in medical insurance costs due to several large claims. Included in noninterest expense in the third quarter of 2015 were technology contract termination and conversion related costs totaling $1.14 million related to the First Bank acquisition.

For the nine months ended September 30, 2016, net income increased 3.88 percent to $78.11 million from $75.19 million a year ago. Basic earnings per share rose to $1.18 from $1.16 in the same period last year. Net interest income increased 6.75 percent to $170.30 million for the nine months ended September 30, 2016, from $159.53 million in the same period a year ago. The provision for loan losses totaled $8.22 million compared with $5.51 million in the same period a year ago. Noninterest income was $63.41 million for the first nine months 2016 compared with $54.15 million in the same period a year ago. Noninterest expense rose to $123.84 million compared with $109.12 million during the same period a year ago.

As of September 30, 2016, consolidated assets for the Company totaled $6.69 billion compared to $6.61 billion at June 30, 2016, and $6.47 billion at September 30, 2015. Loans grew to $3.37 billion at September 30, 2016, compared with loans of $3.31 billion at June 30, 2016 and $3.29 billion at September 30, 2015. Deposits totaled $5.24 billion at September 30, 2016, compared to $5.06 billion at June 30, 2016, and $5.10 billion at September 30, 2015. Shareholders’ equity rose to $867.94 million as of September 30, 2016, compared with $866.16 million at June 30, 2016, and $792.03 million at September 30, 2015.

“We were pleased to see growth in our loans and deposits for the third quarter,” said F. Scott Dueser, Chairman, President and CEO. “We continue to realize the effects that the continued low interest rates, commodity prices, and oil and gas prices have on our balance sheet and income statement. We are encouraged that oil and gas prices have increased and, hopefully, will continue. To counteract the effects of these low prices, we are working hard to grow loans and deposits, while cutting 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.”

About First Financial Bankshares

Headquartered in Abilene, Texas, First Financial Bankshares is a financial holding company that through its subsidiary, First Financial Bank, N.A., operates multiple banking regions with 69 locations in Texas including Abilene, Acton, Albany, Aledo, Alvarado, Beaumont, Boyd, Bridgeport, Brock, Burleson, Cisco, Cleburne, Clyde, Conroe, Cut and Shoot, Decatur, Eastland, Fort Worth, Glen Rose, Granbury, Grapevine, Hereford, Huntsville, Keller, Magnolia, Mauriceville, Merkel, Midlothian, Mineral Wells, Montgomery, Moran, New Waverly, Newton, Odessa, Orange, Port Arthur, Ranger, Rising Star, Roby, San Angelo, Southlake, 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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FIRST FINANCIAL BANKSHARES, INC.

SELECTED FINANCIAL DATA (UNAUDITED)

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FIRST FINANCIAL BANKSHARES, INC.

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