Exhibit 99.1

Civista Bancshares, Inc. Announces Strong Second Quarter 2015 Earnings

Sandusky, Ohio, July 24, 2015 – Civista Bancshares, Inc (NASDAQ:CIVB) PRNewswire (“Civista”) reported net income attributable to common shares of $2.7 million, or $0.29 per diluted share, for the second quarter of 2015, compared with $1.8 million, or $0.21 per diluted share, for the prior year period. For the six-month period ended June 30, 2015, Civista reported net income available to common shareholders of $5.5 million or $0.58 per diluted share, compared to $3.9 million, or $0.43 per diluted share, in the same period of 2014.

“We have posted strong results in the second quarter, which has continued on with the momentum we generated in 2014 and the first quarter of 2015. We ended the quarter with $1 billion in loans for the first time in our organization’s history. We have fully integrated the acquisition of TCNB Financial Corp. and had a full quarter with the acquired locations as part of the Civista family. We have already begun to see improvement in net income as a result.” said James O. Miller, Chairman, President and CEO of Civista.

Results of Operations:

Net interest income for the second quarter of 2015 increased $1.7 million, or 16.1%, from the prior year’s second quarter and for the six months ended June 30 increased $2.4 million, or 11.7%, when compared to the same period of 2014. Tax equivalent net interest margin was 3.96% for the second quarter and 3.81% for the six months ended June 30, 2015. The increase in net interest income for the quarter and six months ended June 30, 2015 was due both to an increase in average loans outstanding as well as a decrease in cost of funds. The average balance of interest-bearing deposits relating to tax refund processing was approximately $73 million for 2015. Removing the impact of Civista’s tax refund processing, the net interest margin would have been 24 basis points higher for the first six months of 2015. Mr. Miller continued, “Due to the cash held as a result of the tax refund processing program we see a decrease in the net interest margin during the first quarter, and gradual improvement as the year progresses. Our second quarter net interest margin is much more reflective of our core net interest margin.”

Summary Average Balance Sheet

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Summary Average Balance Sheet

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The provision for loan losses for the second quarter and six months ended June 30, 2015 decreased $350 thousand, or 46.7%, and $700 thousand, or 46.7%, compared to the three and six-month periods ended June 30, 2014, respectively. Net charge-offs totaled $361 thousand for the first six months of 2015. The decrease in provision for loan losses in the first half of 2015 is primarily related to improved asset quality.

During the quarter, noninterest income totaled $3.7 million, an increase of $272 thousand, or 8.0%, compared to the prior year’s second quarter. Year-to-date noninterest income increased $49 thousand, or 0.8%, when compared to the first six months of 2014.

Service charge income increased in both the three and six-month periods, primarily due to an increase in business service charges, as well as service charge fees instituted in our Dayton market since the acquisition of TCNB Financial Corp (“TCNB”). Gain on sale of loans increased $287 thousand and $388 thousand in the three and six-month periods, respectfully due to additional volume of loans sold as well as an increase in the premium on loans sold. Tax refund processing fees were down $38 thousand, or 8.7% for the second quarter of 2015 compared to the second quarter of 2014 and down $315 thousand, or 13.6% when compared to the six months of 2014, due to a change in the fee structure for 2015.

Mr. Miller continued, “Our mortgage banking operation had a very successful second quarter. We have originated and sold $14.3 million more mortgage loans in the first half of 2015 than we did in the first half of 2014. Our pipeline going forward continues to look strong.”

During the quarter, noninterest expense totaled $10.9 million, an increase of $954 thousand, or 9.6%, compared to the prior year’s second quarter. Year-to-date noninterest expense increased $1.1 million, or 5.5%, when compared to the six months of 2014.

Salaries, wages and benefits expense increased $528 thousand for the second quarter and $700 thousand for the six month period ending June 30, 2015. The increase in salaries, wages and benefits expense was due to normal merit increases, the addition of TCNB employees, as well as a change to our 401k match expense. On January 1, 2015, the 401k plan was modified to a safe harbor plan which increased the mandatory match. Contracted data processing and professional fees increased for both the three and six-month periods ended June 30, 2015. These increases were primarily due to expenses related to the acquisition of TCNB.

Balance Sheet

Total assets increased $104.0 million, or 8.6%, from December 31, 2014 to June 30, 2015. This was due primarily to the acquisition of TCNB, which closed on March 6, 2015. Total assets of TCNB prior to the merger were $97.4 million, including $76.8 million in loans.

Total Loans increased $88.1 million or 9.6% from December 31, 2014 to June 30, 2015. The increase in total loans is primarily due to the acquisition of TCNB which added $76.8 million in loans as well as $11.3 million of net loan originations.

Total deposits increased $106.9 million, or 11.0%, from December 31, 2014 to June 30, 2015. The increase in deposits was primarily due to the acquisition of TCNB, which included $86.9 million in deposits.

Total shareholder’s equity increased $4.1 million, or 3.5%, from December 31, 2014 to June 30, 2015 due to increased retained earnings of $4.7 million and a decrease in Accumulated Other Comprehensive Income of $723 thousand.

Asset Quality

Nonperforming assets at June 30, 2015 were $17.0 million, a $2.0 million decrease from December 31, 2014, and a $5.9 million decrease compared to June 30, 2014.

Mr. Miller continued, “We have continued the momentum we built in 2014 and the first quarter of 2015 and have had a very successful second quarter of 2015. Earnings and asset quality continue to improve, the acquisition of TCNB is fully integrated and we crossed the $1 billion mark in loans. We are optimistic on the prospects for maintaining that momentum for the remainder of 2015.”

Civista Bancshares, Inc. is a $1.3 billion financial holding company headquartered in Sandusky, Ohio. The Company’s banking subsidiary, Civista Bank, operates 28 locations in North Central, West Central and Southwestern Ohio.

Civista Bancshares, Inc. may be accessed at www.civb.com. The Company’s common shares are traded on the NASDAQ Capital Market under the symbol “CIVB”. The Company’s depositary

shares, each representing a 1/40^th ownership interest in a Series B Preferred Share, are traded on the NASDAQ Capital Market under the symbol “CIVBP”.

This press release may contain forward-looking statements regarding the financial performance, business prospects, growth and operating strategies of Civista. For these statements, Civista claims the protections of the safe harbor for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995. Statements in this press release should be considered in conjunction with the other information available about Civista, including the information in the filings we make with the Securities and Exchange Commission. Forward-looking statements provide current expectations or forecasts of future events and are not guarantees of future performance. The forward-looking statements are based on management’s expectations and are subject to a number of risks and uncertainties. We have tried, wherever possible, to identify such statements by using words such as “anticipate,” “estimate,” “project,” “intend,” “plan,” “believe,” “will” and similar expressions in connection with any discussion of future operating or financial performance. Although management believes that the expectations reflected in such forward-looking statements are reasonable, actual results may differ materially from those expressed or implied in such statements. Risks and uncertainties that could cause actual results to differ materially include risk factors relating to the banking industry and the other factors detailed from time to time in Civista’ reports filed with the Securities and Exchange Commission, including those described in “Item 1A Risk Factors” of Part I of Civista’s Annual Report on Form 10-K for the fiscal year ended December 31, 2014. Undue reliance should not be placed on the forward-looking statements, which speak only as of the date hereof. Civista does not undertake, and specifically disclaims any obligation, to publicly release the result of any revisions that may be made to update any forward-looking statement to reflect the events or circumstances after the date on which the forward-looking statement is made, or reflect the occurrence of unanticipated events, except to the extent required by law.

For additional information, contact:

James O. Miller

Chairman, President and CEO

Civista Bancshares, Inc

888-645-4121

Civista Bancshares

Financial Highlights

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Average Balance Analysis

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Supplemental Financial Information

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Supplemental Financial Information

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