Exhibit 99.1

For Immediate Release

Investar Holding Corporation Announces 2015 Fourth Quarter Results

BATON ROUGE, LA (January 28, 2016) – Investar Holding Corporation (NASDAQ: ISTR) (the “Company”), the holding company for Investar Bank (the “Bank”), today announced financial results for the quarter ended December 31, 2015. For the quarter ended December 31, 2015, the Company reported net income of $1.5 million, or $0.20 per diluted share, compared to $2.0 million, or $0.27 per diluted share for the quarter ended December 31, 2014. This represents a decrease of $0.5 million, or 27.6%, in net income which can primarily be attributed to a tax credit realized by the Company in the fourth quarter of 2014.

Core earnings, a non-GAAP measure which excludes the after-tax impact of securities gains and losses, gains and losses on the sale of other real estate owned, and other nonrecurring revenue and costs recorded for the period, were $1.5 million, or $0.21 per diluted share, for the quarter ended December 31, 2015 compared to core earnings of $1.4 million, or $0.19 per diluted share, for the quarter ended December 31, 2014. See calculation of core earnings on the Reconciliation of Non-GAAP Financial Measures.

During the quarter, the Bank announced that it was exiting the indirect auto loan origination business. The Bank discontinued accepting indirect auto loan applications on December 31, 2015, but continued to process and fund applications that were accepted on or before that date. In connection with the discontinuation of the Bank’s indirect auto loan origination business, the Bank incurred exit costs of approximately $145,000, consisting of $76,000 of severance and $69,000 of contract termination costs.

The Bank intends to sell the balance of indirect auto loans classified as held for sale as of year-end. Subsequent to December 31, 2015, the Company has recognized $0.3 million in gain on sale of loans from sales of its indirect auto loans.

Additionally, during the fourth quarter of 2015, the Company realized unfavorable healthcare claims experience in its self-insured health plan maintained for its employees resulting in additional benefits expense of approximately $0.3 million when compared to the third quarter of 2015. The Company believes this experience was unusual and does not expect the high level of claims to continue.

Investar Holding Corporation President and Chief Executive Officer John D’Angelo said:

“We remain focused on growing our franchise and delivering value to our shareholders. We were pleased with our earnings for the year and excited to have met our internal growth targets for both total loans and noninterest-bearing deposits. Credit quality remains strong and we will continue to focus our efforts on making quality credit decisions.

We took proactive steps during the quarter to better position the Company moving in to 2016 by hiring three additional commercial lenders while making the strategic decision to exit the indirect auto loan origination business. The decision was based on the operating performance of the indirect auto loan origination business unit and our desire to focus resources on relationship banking opportunities. We believe the shift from transactional banking to relationship banking will enhance value for our shareholders. We intend to remain focused on smart growth through the recent addition of quality commercial lenders and the continued bank-wide focus on growing noninterest-bearing deposits.”

Fourth Quarter Highlights

Loans

Total loans were $745.4 million at December 31, 2015, an increase of $122.7 million, or 19.7%, from December 31, 2014.

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 $196.0 million at December 31, 2015, a decrease of $18.0 million, or 8.4% from $214.0 million at December 31, 2014. The decrease is mainly attributable to the $19.8 million decrease in the balance of consumer loans held for sale at December 31, 2015 when compared to December 31, 2014. Two consumer loan sales were postponed by the buyer from the fourth quarter of 2014 to the first quarter of 2015, therefore increasing the balance of consumer loans held for sale at December 31, 2014. In addition, in November the Company announced that the Bank will exit the indirect auto loan origination business but would be accepting indirect auto loan applications through December 31, 2015. Our impending exit from the business negatively impacted the volume of loans originated for sale in the fourth quarter of 2015 when compared to prior quarters.

At December 31, 2015, the Company’s total business lending portfolio, which consists of loans secured by owner-occupied commercial real estate properties and commercial and industrial loans, was $207.7 million, an increase of $33.8 million, or 19.5%, compared to the business lending portfolio of $173.9 million at December 31, 2014.

Management continues to monitor the Company’s loan portfolio for exposure, directly or indirectly, to the potential negative impacts from the fluctuation in oil and gas prices. Less than 1% of the total loan portfolio remains directly related to the energy sector. At this time, management does not anticipate that decreases in oil and gas prices will negatively impact borrowers’ ability to service their debt. Management continually evaluates the allowance for loan losses based on several factors, including economic conditions, and currently believes that any potential negatively affected future cash flows related to these loans would be covered by the allowance for loan losses.

The provision for loan loss expense was $0.4 million for the fourth quarter of both 2015 and 2014. The allowance for loan losses was $6.1 million, or 254.16% and 0.82% of nonperforming loans and total loans, respectively, at December 31, 2015, compared to $4.6 million, or 138.61% and 0.74% of nonperforming loans and total loans, respectively, at December 31, 2014. The allowance for loan losses plus the fair value marks on acquired loans was 0.91% of total loans at December 31, 2015 compared to 0.88% at December 31, 2014. Nonperforming loans to total loans improved to 0.32% at December 31, 2015 compared to 0.54% at December 31, 2014.

Deposits

Total deposits at December 31, 2015 were $737.4 million, an increase of $109.3 million, or 17.4%, from December 31, 2014. The increase in total deposits was driven primarily by an increase in noninterest-bearing demand deposits of $20.2 million, or 28.8%, an increase in NOW accounts of $23.9 million, or 20.5%, and an increase in time deposits of $46.3 million, or 14.9%, from December 31, 2014. The Company’s focus on relationship banking, including our deposit cross sell strategy, as well as management’s focus on growing the commercial and industrial loan portfolio and bringing in related deposits, continues to positively 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 2015 totaled $8.2 million, an increase of $0.3 million, or 3.5%, compared to the third quarter of 2015, and an increase of $0.6 million, or 8.6%, compared to the fourth quarter of 2014. The increase was a direct result of continued growth of the Company’s loan portfolio with an increase in net interest income of $1.4 million due to an increase in volume offset by a $0.8 million decrease related to a reduction in yield compared to the fourth quarter of 2014.

The Company’s net interest margin was 3.53% for the quarter ended December 31 , 2015 compared to 3.52% for the third quarter of 2015 and 3.84% for the fourth quarter of 2014. The yield on interest-earning assets was 4.24% for the quarter ended December 31 , 2015 compared to 4.20% for the third quarter of 2015 and 4.47% for the fourth quarter of 2014. The decrease in both the net interest margin and yield on interest-earning assets compared to the fourth quarter of 2014 can be attributed to the consumer loan portfolio. The consumer loan portfolio primarily consists of indirect auto loans and has experienced margin compression related to its current originations.

The cost of deposits increased 1 basis point when comparing the fourth quarter of 2015 to the third quarter of 2015, and increased 5 basis points when comparing the fourth quarter of 2015 to the fourth quarter of 2014.

Noninterest Income

Noninterest income for the fourth quarter of 2015 totaled $1.6 million, a decrease of $0.6 million, or 27.5%, compared to the third quarter of 2015, and an increase of $0.2 million, or 18.6%, compared to the fourth quarter of 2014. The decrease in noninterest income compared to the third quarter of 2015 is mainly attributable to the $0.5 million decrease in gain on sale of loans related to the timing of loan sales.

The following table sets forth the composition of the Company’s gain on sale of loans for the time periods indicated (dollars in thousands):

The increase in noninterest income from the fourth quarter of 2014 resulted primarily from the $0.3 million increase in other operating income, offset by a $0.1 million decrease in gain on sale loans. The increase in other operating income is mainly attributable to the $0.3 million increase in servicing fees, a direct result of the growth in the Company’s servicing portfolio from consumer loan sales.

Core noninterest income, which excludes the gains and losses on the sales of investment securities and other real estate owned, was $1.5 million for the fourth quarter of 2015, a decrease of $0.5 million, or 23.5%, compared to $2.0 million for the third quarter of 2015, and an increase of $0.3 million, or 24.0%, compared to $1.2 million for the fourth quarter of 2014.

Noninterest Expense

Noninterest expense for the fourth quarter of 2015 totaled $7.2 million, an increase of $0.2 million, or 3.1%, compared to the third quarter of 2015, and an increase of $0.3 million, or 4.0%, compared to the fourth quarter of 2014. The increase in noninterest expense from the fourth quarter of 2014 is primarily due to the $0.5 million increase in salaries and employee benefits and the $0.1 million increase in both other operating expenses and professional fees, all of which are mainly attributable to the continued growth of the

Company. Furthermore , t he Company provides health insurance to its employees through a sel f-insured plan and realiz ed unfavorable health care claims experience during the fourth quarter of 2015 resulting in additional benefits expense of approximately $0.3 million.

During the fourth quarter of 2015, the Company incurred nonrecurring exit costs of approximately $145,000. These costs included severance, which contributed to the $0.5 million increase in salaries and benefits discussed above, and other expenses related to the exit from the indirect auto loan origination business, announced in November 2015. Core noninterest expense, which excludes the impact of these nonrecurring costs, was $7.1 million for the fourth quarter of 2015, an increase of $0.5 million, or 6.7%, compared to $6.6 million in the third quarter of 2015, and an increase of $0.8 million, or 13.1%, compared to the fourth quarter of 2014.

Basic Earnings Per Share and Diluted Earnings Per Share

The Company reported both basic and diluted earnings per share of $0.20 for the three months ended December 31 , 2015, a decrease of $0.08 and $0.07, respectively, compared to basic and diluted earnings per share of $0.28 and $0.27, respectively, for the three months ended December 31, 2014.

Core basic and diluted earnings per share were $0.21 for the three months ended December 31, 2015, an increase of $0.02 compared to core basic and diluted earnings per share of $0.19 for the three months ended December 31, 2014.

Taxes

The Company recorded income tax expense of $0.7 million for the quarter ended December 31 , 2015, which equates to an effective tax rate of 33.9%.

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 , 2015, the Company had 168 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 common equity,” “tangible assets,” “tangible equity to tangible assets,” “tangible book value per common share,” “efficiency ratio,” “core noninterest income,” “core earnings before noninterest expense,” “core noninterest expense,” “core income tax expense,” “core earnings,” “core efficiency ratio,” “core return on average assets,” “core return on average equity,” “core basic earnings per share,” and “core diluted earnings per share.” 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 c o ntai n s forward- l ooking s t a t eme n ts wit h in t h e mean i ng of t h e Priva t e Securities Lit i gati o n Ref o rm Act of 1 9 95 that reflect the Company’s current views w i t h res p ec t t o , amo n g ot h er th i ngs , fu t u re e v e n t s a n d f i nancia l pe r f o r mance . T h e C o m p any ge n eral l y i d entifies forward-l o ok i ng statemen t s by termi n ol o g y such as “outlook,” “believes,” “expects,” “ potential,” “continue s,” “may,” “will,” “could,” “ s hould,” “seek s ,” “approximately,” “pred i ct s ,” “intends,” “plan s ,” “esti m ates,” “anticipates,” or the ne g ative ve rs io n of th o s e w o rd s o r o t he r compa r abl e wo r ds . A n y f o rwa r d - lo oking s t atem e nts contained in this press relea s e are based on t he h i s t o r ica l pe r f o r ma n c e o f t h e Compa n y a n d i t s subs i dia r ie s o r on the Company’s cur r ent plan s , estimates and expectation s . The i n clusi o n of thi s forward-lo o ki n g i n f o rmati o n s h oul d n ot be re g arded as a repres e ntation by the Company that the future plans, estimates or e x pecta t ions by t h e Compa n y will be ach i eved. S u ch forward-lo o k i n g statemen t s are sub j ect t o vari o u s

r i sks a n d uncerta i n t i es and assump t i ons relat i ng to t h e Compan y ’ s operati o ns, fina n cial results, fi n ancial co n d i t io n , business p r ospects, g ro w t h st ra teg y a n d li q ui d it y . If o ne o r mo re of t h es e or o t he r r isk s o r unce r tai n tie s ma t e r i a l ize , or i f th e C o m p any ’s u nde r l y in g as s ump t io n s prove to be incorrect, the Company ’ s actual r es u lts m ay v ary m ate ri ally f r om t h os e indicated in these s t atement s . The Company d oes n ot un d er t a k e an y o b li g ati o n t o p u bl i c l y u p dat e or re v ie w an y f o r wa r d- l oo k in g s t ateme n t , w het h er a s a re s u l t o f ne w i n fo rm atio n, f ut u r e deve l opmen t s or ot h e r w ise . A n u m b e r o f impo r tan t f act o rs cou l d cause ac t ual results to d i ffer materially from t h ose in d icated b y th e f or w ar d -l o ok i n g sta t ements. These factors include, but are not limi t ed to, the fol l ow i ng, any one or more of which co u l d mater i ally affect t h e o u t c ome of future events:

• o ur ab i li ty to ac hi eve o rg a n ic loan a n d dep o sit g r ow t h , a n d th e comp o s i ti o n o f t ha t g r ow t h ;

• t h e exte n t o f co n ti n ui n g cl i e n t de ma n d f o r th e h ig h leve l o f pe rs onal i ze d se r vic e t ha t i s a ke y e l emen t o f ou r ba n ki n g

approa c h a s well as our abili t y to execute our strate g y general ly ;

• o ur de p e nde n c e on ou r man agement team, and our abili t y to attract and retain q u al i f ied personnel;

• inaccuracy of the assumptions and estimat e s we make in establishing reserves for p r obable loan lo s ses and other estimates;

• the concentration of ou r b u s i ne s s wi t hi n o u r ge og raphic areas of operat i on in L o uisia n a; and

• concentration of credit exposure.

These factors should not be con s tru e d as exha u s tive . Ad d it i ona l i n f o rmati o n on thes e an d ot h er ris k f acto rs ca n b e fo u n d i n I t em 1 A. “Risk Factor s ” and Item 7. “Special Note Rega r di n g Fo r wa r d-L o ok i n g S t atement s ” i n t h e C ompan y ’ s A nn u a l Re p o rt on Fo rm 1 0-K for the year end e d December 31, 2014, f i led wi t h the Secu r ities and Exchange Commission.

For further information contact:

Investar Holding Corporation

Chris Hufft

Chief Financial Officer

(225) 227-2215

Chris.Hufft@investarbank.com