Exhibit 99.1

For Immediate Release

Investar Holding Corporation Announces 2014 Fourth Quarter Results

Investar Holding Corporation Achieves Record Growth in Net Income of 1,028%

BATON ROUGE, LA (January 28, 2015) – Investar Holding Corporation (NASDAQ: ISTR) (the “Company”), the holding company for Investar Bank, today announced financial results for the quarter and year ended December 31, 2014. For the quarter ended December 31, 2014, the Company reported net income of $2.0 million, or $0.27 per diluted share, compared to $0.2 million, or $0.04 per diluted share for the quarter ended December 31, 2013. This represents an increase of $1.8 million, or 1,028%, in net income. For the year ended December 31, 2014, the Company reported net income of $5.4 million, or $0.93 per diluted share, compared to $3.2 million, or $0.81 per diluted share, for the year ended December 31, 2013. This represents an increase of $2.2 million, or 70.4%, in net income. After adjusting for the net effect of an investment in a tax credit entity, discussed in “Taxes” below, net income was $1.5 million, or $0.20 per diluted share, for the quarter ended December 31, 2014, compared to $0.2 million, or $0.04 per diluted share, for the comparable quarter in 2013, an increase in net income of 733.84%, or $0.16 per diluted share.

Investar Holding Corporation President and Chief Executive Officer John D’Angelo said, “Our board and management are very happy with our achievements and performance in 2014. We completed our IPO, realized a record year in profitability and loan originations and maintained a delinquency ratio significantly below our peers. We are very pleased with our organic growth and continue to drive more earnings to the bottom line as we grow into our infrastructure.”

Performance Highlights

Loans

Total loans were $622.8 million at December 31, 2014, an increase of $118.7 million, or 23.5%, from December 31, 2013.

The following table sets forth the composition of the Company’s loan portfolio as of the dates indicated (dollars in thousands):

Consumer loans, including consumer loans held for sale, totaled $214.0 million at December 31, 2014, an increase of 63.2% from $131.1 million at December 31, 2013. At December 31, 2013, there were no consumer loans held for sale. Due to the increase in production and the timing of loan pool sales, the Company increased its consumer held for sale portfolio to $99.7 million at December 31, 2014. Two loan pool sales totaling approximately $52.0 million were moved from the fourth quarter of 2014 to the first quarter of 2015 and have been completed subsequent to December 31, 2014.

At December 31, 2014, the Company’s total business lending portfolio, which consists of loans secured by owner occupied nonfarm, nonresidential properties and commercial and industrial loans, was $173.9 million, an increase of $22.0 million, or 14.5%, compared to the business lending portfolio of $151.9 million at September 30, 2014 and an increase of $62.8 million, or 56.5%, compared to the business lending portfolio of $111.1 million at December 31, 2013.

We have reviewed our loan portfolio for exposure, directly or indirectly, to the potential negative impacts from the fluctuation in oil and gas prices. We have identified less than one percent of our total loan portfolio with a relationship to the energy sector. At December 31, 2014, none of the loans identified were past due. At this time, we are not concerned that decreases in oil and gas prices will negatively impact our borrowers’ ability to service their debt. Our allowance for loan losses is continuously evaluated based on several factors, including economic conditions, and we believe that any potential negatively affected future cash flows related to these loans would be covered by our allowance for loan losses.

The provision for loan loss expense was $0.4 million for the fourth quarter of 2014, a decrease of $0.3 million compared to the fourth quarter of 2013. The allowance for loan losses was $4.6 million, or 138.61% and 0.74% of nonperforming loans and total loans, respectively, at December 31, 2014, compared to $3.4 million, or 227% and 0.67% of nonperforming loans and total loans, respectively, at December 31, 2013.

Nonperforming assets totaled $6.1 million at December 31, 2014, an increase of $1.1 million compared to December 31, 2013. The ratio of total nonperforming assets to total assets was 0.69% at December 31, 2014, compared to 0.79% at December 31, 2013.

Deposits

Total deposits at December 31, 2014 were $628.1 million, an increase of $95.5 million, or 17.9%, from December 31, 2013. The increase in total deposits was driven primarily by an increase of $11.4 million, or 19.4%, in noninterest bearing demand deposits after adjusting for a $14 million short term deposit made by a commercial customer in late December 2013 that was fully withdrawn in January 2014, an increase in NOW accounts of $39.5 million, or 51.1%, and an increase in time deposits of $46.9 million, or 17.8%, from December 31, 2013. We believe our deposit cross sell strategy continues to impact both noninterest bearing demand deposit and NOW account growth.

The following table sets forth the composition of the Company’s deposits as of the dates indicated (dollars in thousands):

Net Interest Income

Net interest income for the fourth quarter of 2014 totaled $7.6 million, an increase of $2.0 million, or 35.2%, from the fourth quarter of 2013. The increase was a direct result of continued growth of the Company’s loan portfolio with an increase in net interest income of $2.3 million due to an increase in volume offset by a $0.3 million decrease related to a reduction in yield when compared to the fourth quarter of 2013.

Net interest income for the year ended December 31, 2014 totaled $26.7 million, an increase of $7.7 million, or 40.4%, from the year ended December 31, 2013. This increase was also a direct result of continued growth of the Company’s loan portfolio with an increase in net interest income of $9.2 million due to an increase in volume offset by a $1.5 million decrease related to a reduction in yield when compared to the year ended December 31, 2013.

The Company’s net interest margin was 3.84% for the quarter ended December 31, 2014 compared to 3.86% for the third quarter of 2014 and 4.01% for the fourth quarter of 2013. The decrease in the net interest margin since 2013 can be attributed to lower yields on the real estate and consumer loan portfolios. The yield on interest earning assets was 4.47% for the quarter ended December 31, 2014 compared to 4.51% for the third quarter of 2014 and 4.72% for the fourth quarter of 2013. The cost of deposits declined one basis point when comparing the fourth quarter of 2014 to the third quarter of 2014, and declined three basis points when comparing the fourth quarter of 2014 to the fourth quarter of 2013.

The Company’s net interest margin was 3.85% for the year ended December 31, 2014 compared to 4.10% for the year ended December 31, 2013. The decline in the interest margin can be attributed to lower yields primarily on the construction, multifamily and nonfarm, nonresidential loan portfolios.

Noninterest Income

Noninterest income for the fourth quarter of 2014 totaled $1.3 million, an increase of $0.4 million, or 36.7%, compared to the fourth quarter of 2013. Noninterest income, excluding securities gains, for the fourth quarter of 2014 totaled $1.2 million, an increase of $0.4 million, or 40.5% compared to the fourth quarter of 2013. The increase resulted primarily from the increase of $0.2 million in other operating income and the increase of $0.1 million in gain on sale of consumer loans.

Noninterest income for the year ended December 31, 2014 totaled $5.9 million, an increase of $0.5 million, or 9.5%, compared to the year ended December 31, 2013. Noninterest income, excluding securities gains and the $0.9 million bargain purchase gain recorded in the second quarter of 2013 in connection with the Company’s acquisition of First Community Bank in May 2013, increased $1.5 million for the year ended December 31, 2014 compared to the year ended December 31, 2013 primarily as a result of the increase of approximately $1.4 million in gain on sale of consumer loans and increases in our servicing and other fee income offset by the $0.7 million decline in fee income on mortgage loans held for sale.

Noninterest Expense

Noninterest expense for the fourth quarter of 2014 totaled $7.0 million, an increase of $1.3 million, or 23.8%, compared to the fourth quarter of 2013. The increase in noninterest expense is primarily due to the $0.4 million increase in salaries and employee benefits, the $0.1 million increase in both occupancy and equipment expense and data processing expense and the $0.7 million increase in impairment on investment in tax credit entity recognized as a result of the Federal Historic Rehabilitation tax credit project completed in December 2014. The increases in salaries and benefits, occupancy and equipment and data processing expenses are attributable to the Company’s expansion into the Lafayette, Louisiana region, which included the opening of a branch in the fourth quarter of 2013, the opening of the Highland Road branch in Baton Rouge, Louisiana on August 1, 2014 and the addition of 16 full-time equivalent employees.

Noninterest expense for the year ended December 31, 2014 totaled $24.4 million, an increase of $5.4 million, or 28.2%, compared to the year ended December 31, 2013. The increase is attributable to the full twelve months of expenses associated with the two branches that the Company acquired as a result of the First Community Bank acquisition in May 2013 and the Company’s expansion into the Lafayette region, which included the opening of a branch during the fourth quarter 2013, as well as the additional expenses related to the opening of the Highland Road branch during the third quarter of 2014. Other factors include the impairment charge on the investment in the tax credit entity related to the Federal Historic Rehabilitation tax credit project, mentioned above, and the professional fees related to the Company’s implementation of Sarbanes-Oxley compliance.

Basic Earnings Per Share and Diluted Earnings Per Share

The Company reported basic earnings per share and diluted earnings per share of $0.28 and $0.27, respectively, for the three months ended December 31, 2014, an increase of $0.08 and $0.07, respectively, compared to the three months ended September 30, 2014 and an increase of $0.23 and $0.23, respectively, when compared to the three months ended December 31, 2013.

The Company reported basic earnings per share and diluted earnings per share for the year ended December 31, 2014 of $0.98 and $0.93, an increase of $0.12 and $0.12, respectively, compared to the year ended December 31, 2013. Excluding the net effect of the Company’s investment in the Federal Historic Rehabilitation tax credit project during the fourth quarter of 2014, diluted earnings per share for the year ended December 31, 2014 was $0.85, an increase of $0.23, after adjusting for the bargain purchase gain and acquisition related expenses for the year ended December 31, 2013.

Taxes

The Company recorded income tax (benefit) expense of $(0.5) million and $1.1 million for the quarter and year ended December 31, 2014, respectively, which equates to an effective tax rate of (32.4)% and 17.5%, respectively. During the fourth quarter of 2014, the Company invested in a tax credit entity whose purpose was to invest in a Federal Historic Rehabilitation tax credit project. As a result of the investment, the Company recognized a tax credit of $1.0 million, reducing tax expense for the quarter and year ended December 31, 2014, as well as a corresponding impairment on the investment in the tax credit entity of $0.7 million. Due to the net effect of the investment, the Company experienced an effective tax rate below the statutory rate of 35%.

About Investar Holding Corporation

Investar Holding Corporation, headquartered in Baton Rouge, Louisiana, provides full banking services, excluding trust services, through its wholly-owned banking subsidiary, Investar Bank, a state chartered bank. The Company’s primary market is South Louisiana and it currently operates 11 full service banking offices located throughout its market. At December 31, 2014, the Company had 179 full-time equivalent employees.

Non-GAAP Financial Measures

This press release contains financial information determined by methods other than in accordance with generally accepted accounting principles in the United States of America, or GAAP. These measures and ratios include “tangible book value,” “tangible book value per common share,” “efficiency ratio,” “tangible equity to tangible assets,” “adjusted efficiency ratio,” and “adjusted return on equity.” Management also utilizes non-GAAP performance measures to adjust net income for certain significant activities or transactions that are infrequent in nature. Management believes these non-GAAP financial measures provide information useful to investors in understanding the Company’s financial results, and the Company believes that its presentation, together with the accompanying reconciliations, provide a more complete understanding of factors and trends affecting the Company’s business and allow investors to view performance in a manner similar to management, the entire financial services sector, bank stock analysts and bank regulators. These non-GAAP measures should not be considered a substitute for GAAP basis measures and results, and the Company strongly encourages investors to review its consolidated financial statements in their entirety and not to rely on any single financial measure. Because non-GAAP financial measures are not standardized, it may not be possible to compare these financial measures with other companies’ non-GAAP financial measures having the same or similar names. A reconciliation of the non-GAAP financial measures disclosed in this press release to the comparable GAAP financial measures is included at the end of the financial statement tables.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 that reflect the Company’s current views with respect to, among other things, future events and financial performance. The Company generally identifies forward-looking statements by terminology such as “outlook,” “believes,” “expects,” “potential,” “continues,” “may,” “will,” “could,” “should,” “seeks,” “approximately,” “predicts,” “intends,” “plans,” “estimates,” “anticipates,” or the negative version of those words or other comparable words. Any forward-looking statements contained in this press release are based on the historical performance of the Company and its subsidiaries or on the Company’s current plans, estimates and expectations. The inclusion of this forward-looking information should not be regarded as a representation by the Company that the future plans, estimates or expectations by the Company will be achieved. Such forward-looking statements are subject to various risks and uncertainties and assumptions relating to the Company’s operations, financial results, financial condition, business prospects, growth strategy and liquidity. If one or more of these or other risks or uncertainties materialize, or if the Company’s underlying assumptions prove to be incorrect, the Company’s actual results may vary materially from those indicated in these statements. These factors should not be construed as exhaustive. The Company does not undertake any obligation to publicly update or review any forward-looking statement, whether as a result of new information, future developments or otherwise. A number of important factors could cause actual results to differ materially from those indicated by the forward-looking statements. Information on these factors can be found in the filings that the Company makes with the Securities and Exchange Commission.

For further information contact:

Investar Holding Company

John D’Angelo

President and Chief Executive Officer

(225) 448-5461

John.Dangelo@investarbank.com

Investar Holding Company

Chris Hufft

Chief Accounting Officer

(225) 227-2215

Chris.Hufft@investarbank.com

INVESTAR HOLDING CORPORATION

CONSOLIDATED BALANCE SHEETS

(Amounts in thousands, except share data)