Exhibit 99.1

Civista Bancshares, Inc. Announces Second Quarter 2017 Earnings

Sandusky, Ohio, July 28, 2017 /PRNewswire/– Civista Bancshares, Inc. (NASDAQ:CIVB) (“Civista”) reported net income available to common shareholders of $3.3 million, or $0.29 per diluted share, for the second quarter of 2017, compared with $4.8 million, or $0.47 per diluted share, for the prior year period. For the six-month period ended June 30, 2017, Civista reported net income available to common shareholders of $7.6 million or $0.68 per diluted share, compared to $9.1 million, or $0.91 per diluted share, in the same period of 2016. The 2016 results for both the second quarter and six-month period were impacted by a large loan recovery that resulted in a negative provision of $1.3 million and a recovery of interest income of over $900 thousand before taxes and approximately $1.5 million after taxes. In addition, we issued approximately 1.6 million new shares in February related to raising $32.8 million of additional capital, net of costs.

“When we remove the impact of the 2016 loan recovery, our net income for the 2017 periods is comparable to 2016. Our noninterest expenses have increased during the year due to lending staff increases in our new Westlake, Ohio office and additional lenders in our Mayfield Heights and Dublin, Ohio, markets. We have already seen some results from these lenders and view their hires as an investment in future growth of the company” said James O. Miller, Chairman, President and CEO of Civista.

Results of Operations:

Net interest income for the second quarter of 2017 increased $427 thousand, or 3.3% compared to the same period of 2016 and for the six months ended June 30 increased $1.1 million, or 4.3%, when compared to the same period of 2016. For the three and six-month periods ended June 30, an increase in average loans outstanding primarily contributed to the increase in interest income compared to 2016. The increase in loan volume was mitigated by a decrease in loan yield. The net interest income for both periods in 2016 included approximately $900 thousand of recovered interest income on a previous non-accrual loan. Tax equivalent net interest margin was 4.05% for the second quarter, compared to 4.13% for the same period a year ago and was 3.86% for the six months ended June 30, 2017, compared to 3.81% for the same period a year ago. Net interest margin was reduced in both periods due to the impact of additional interest-earning cash on deposit related to the tax refund processing program. The impact to net interest margin related to the tax refund processing program through June 30 was a reduction of 16 basis points in 2017 and 38 basis points in 2016.

Summary Average Balance Sheet

(Tax-equivalent basis / dollars in thousands)

Summary Average Balance Sheet

(Tax-equivalent basis / dollars in thousands)

No provision for loan losses was made for the second quarter and six months ended June 30, 2017, while the provision was negative $1.3 million for the second quarter and six months ended June 30, 2016.

During the quarter, noninterest income totaled $4.1 million, an increase of $26 thousand, compared to the prior year’s second quarter. Year-to-date noninterest income totaled $9.2 million, a decrease of $98 thousand, or 1.0%, compared to the prior year’s first six months.

Noninterest income

Service charge income for the three-month period this year compared to last year were flat but decreased $88 thousand, or 3.5%, for the six-month period ended June 30, 2017 compared to 2016, primarily due to an increase in the business account earnings credits. Overdraft charges were also down, related to consumer account activity. Gain on sale of loans increased $72 thousand, or 17.7%, for the three-month period ended June 30, but remain down $65 thousand, or 8.1% for the year. The six-month period ended June 30, 2016 included a gain associated with Commercial loans which totaled $77 thousand. Wealth management fees increased $72 thousand and $145 thousand for the three-month and six-month periods ended June 30, 2017 and 2016. Assets under management have increased $21.4 million since the end of the first quarter 2017 and $38.1 million since the end of the second quarter 2016.

During the quarter, noninterest expense totaled $12.5 million, an increase of $1.5 million, or 13.5%, compared to the prior year’s second quarter. Year-to-date noninterest expense increased $2.1 million, or 9.5%, when compared to the six months of 2016.

Noninterest expense

Salaries, wages and benefits expense increased $824 thousand for the second quarter and $1.6 million for the six-month period ending June 30, 2017. The increases in salaries, wages and benefits expense for both periods were due to an increase in employees, normal merit raises, as well as increases in incentives, insurance costs and pension expense. ATM expenses increased $139 thousand for the second quarter and $272 thousand for the six-month period ending June 30, 2017. The increases are primarily due to vendor credits that expired in the second quarter of 2016 and expenses incurred related to the Company’s debit card program conversion. Professional services costs increased $216 thousand for the second quarter and $165 thousand for the six-month period ending June 30, 2017. The increase for both periods was primarily attributable to the Company retaining professional services to analyze its’ workflow systems and recommend process improvements.

The efficiency ratio was 66.3% for the six months ended June 30, 2017 compared to 62.4% for the six months ended June 30, 2016. The increase in the efficiency ratio is due primarily to the increase in noninterest expense, partially offset by an increase in net interest income. The recovery of interest income in 2016 accounted for 168 basis points of the change.

Balance Sheet

Total assets increased $84.8 million, or 6.2%, from December 31, 2016 to June 30, 2017, primarily due to an increase in the loan portfolio of $45.3 million and an increase in investment securities of $34.3 million.

The $45.3 million, or 4.3%, increase in the loan portfolio from December 31, 2016 to June 30, 2017 continues to come from growth in our Commercial and Agriculture, Commercial Real Estate and Residential Real Estate loan portfolios.

End of period loan balances

(dollars in thousands)

Mr. Miller continued, “June 2017 marks the first quarter that we have ended with more than $1.1 billion in gross loans. Our annualized growth for 2017 is 8.6%. The addition of several lenders and the opening of the Westlake, Ohio loan production office have provided a good foundation for growth.”

Total deposits increased $43.8 million, or 3.9%, from December 31, 2016 to June 30, 2017. The increase was due primarily to the additional cash balances related to the tax refund processing program.

End of period deposit balances

(dollars in thousands)

Federal Home Loan Bank advances increased $14.8 million or 30.5% from December 31, 2016 to June 30, 2017, primarily to fund loan growth.

Total shareholders’ equity increased $41.2 million, or 30.0%, from December 31, 2016 to June 30, 2017, primarily due to approximately $32.8 million of additional common equity raised in February. Retained earnings also increased by $6.5 million.

Asset Quality

The Company recorded net charge-offs of $258 thousand for the first half of 2017 compared to net recoveries of $1.5 million for the same period of 2016.

Non-performing assets at June 30, 2017 were $10.8 million, a 7.5% decrease from December 31, 2016.

Civista Bancshares, Inc. is a $1.5 billion bank holding company headquartered in Sandusky, Ohio. The Company’s banking subsidiary, Civista Bank, operates 29 locations in Northern, Mid-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, 2016. 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 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, Inc.

Financial Highlights

(dollars in thousands, except share amounts)

Consolidated Condensed Statement of Income

Selected Balance Sheet Items

Average Balance Analysis

(Unaudited – Dollars in thousands except share data)

* - All yields and costs are presented on an annualized basis

Average Balance Analysis

(Unaudited – Dollars in thousands except share data)

* - All yields and costs are presented on an annualized basis

Supplemental Financial Information

(Unaudited – Dollars in thousands except share data)

Supplemental Financial Information

(Unaudited – Dollars in thousands except share data)