Financial Data as of First Quarter 2024

2 CERTAIN IMPORTANT INFORMATION CAUTION REGARDING FORWARD LOOKING STATEMENTS This presentation contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended with respect to the financial condition, liquidity, results of operations, and future performance of the business of First Guaranty Bancshares, Inc. (“First Guaranty,” the “Company” or “FGBI”). These forward-looking statements are intended to be covered by the safe harbor for “forward-looking statements” provided by the Private Securities Litigation Reform Act of 1995. Forward-looking statements are those that are not historical facts. Forward-looking statements include statements with respect to beliefs, plans, objectives, goals, expectations, anticipations, estimates and intentions that are subject to significant risks and uncertainties and are subject to change based on various factors (some of which are beyond our control). Forward-looking statements often include the words “believes,” “expects,” “anticipates,” “estimates,” “forecasts,” “intends,” “plans,” “targets,” “potentially,” “probably,” “projects,” “outlook” or similar expressions or future conditional verbs such as “may,” “will,” “should,” “would” and “could.” We caution you that any such forward-looking statements are not guarantees of future performance and are subject to risks, assumptions and uncertainties that are difficult to predict. These forward-looking statements are subject to a number of factors and uncertainties, including, changes in general economic conditions, either nationally or in our market areas, that are worse than expected; competition among depository and other financial institutions; inflation and changes in the interest rate environment that reduce our margins or reduce the fair value of financial instruments; adverse changes in the securities markets; changes in laws or government regulations or policies affecting financial institutions, including changes in regulatory fees and capital requirements; our ability to enter new markets successfully and capitalize on growth opportunities; our ability to successfully integrate acquired entities; changes in consumer spending, borrowing and savings habits; changes in accounting policies and practices, as may be adopted by the bank regulatory agencies, the Financial Accounting Standards Board, the Securities and Exchange Commission and the Public Company Accounting Oversight Board; changes in our organization, compensation and benefit plans; changes in our financial condition or results of operations that reduce capital available to pay dividends; increases in our provision for loan losses and changes in the financial condition or future prospects of issuers of securities that we own, which could cause our actual results and experience to differ from the anticipated results and expectations, expressed in such forward-looking statements. We undertake no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise. Although we believe that the expectations reflected in these forward-looking statements are reasonable as of the date made, actual results may prove to be materially different from the results expressed or implied by the forward-looking statements. NON-GAAP FINANCIAL MEASURES Statements included in this presentation include non-GAAP financial measures and should be read along with the accompanying tables under the section titled “Non-GAAP Reconciliations.” The Company uses non-GAAP financial measures to analyze its performance. Management believes that non-GAAP financial measures provide additional useful information that allows readers to evaluate the ongoing performance of the Company and provide meaningful comparison to its peers. Non-GAAP financial measures should not be considered as an alternative to any measure of performance or financial condition as promulgated under GAAP, and investors should consider the Company’s performance and financial condition as reported under GAAP and all other relevant information when assessing the performance or financial condition of the Company. Non-GAAP financial measures have limitations as analytical tools, and investors should not consider them in isolation or as a substitute for analysis of the results or financial condition as reported under GAAP.

FIRST GUARANTY BANCSHARES, INC.

4 FINANCIAL HIGHLIGHTS  Total assets increased YoY by 9.8% to $3.6 billion  Total loans increased YoY by 6.9% to $2.8 billion  QTD net income of $2.3 million  QTD earnings per common share of $0.14  Net interest income increased $0.9 million in 1Q compared to 4Q.  Net interest margin was increased by 5 bps to 2.58% in 1Q compared to 2.53% in 4Q.  Return on average assets of 0.26% for 1Q 2024  Return on average common equity of 3.17% for 1Q 2024  Allowance for credit losses totaled $31.5 million, 1.14% of gross loans  Reserve for unfunded commitments in other liabilities totaled $2.6 million at 03/31/2024.  Strong liquidity resources. On and off-balance sheet 2024 HIGHLIGHTS ¹Non-GAAP measure. See “Certain Important Information – Non-GAAP Financial Measures” on slide 2 Source: Company documents In $000s except for per share data 12/31/2021 12/31/2022 12/31/2023 1Q2024 BALANCE SHEET Total Assets $2,878,120 $3,151,347 $3,552,772 $3,555,791 Total Gross Loans $2,159,359 $2,519,077 $2,748,708 $2,752,230 Total Deposits $2,596,492 $2,723,792 $3,009,094 $3,063,876 Loans/Deposits 83.16% 92.48% 91.35% 89.83% CAPITAL Common Equity $190,831 $201,933 $216,573 $217,262 Preferred Equity $33,058 $33,058 $33,058 $33,058 Total Equity/Assets 7.78% 7.46% 7.03% 7.04% Tang. Common Equity/Tang. Assets1 6.04% 5.89% 5.65% 5.67% PROFITABILITY MEASURES Net Interest Margin 3.44% 3.47% 2.69% 2.58% Net Interest Income/Average Assets 3.31% 3.35% 2.60% 2.50% * Non Interest Expense/Average Assets 2.36% 2.38% 2.45% 2.15% * Efficiency Ratio 63.63% 63.94% 83.62% 78.15% Cost of funds 1.11% 1.66% 3.90% 4.38% ROACE 14.06% 13.64% 3.36% 3.17% Earnings Per Common Share 2.42$ 2.48$ 0.62$ 0.14$ Net Income $27,297 $28,884 $9,219 $2,310 ASSET QUALITY NPAs/Total Assets 0.70% 0.47% 1.17% 1.25% Reserves/Total Loans 1.11% 0.93% 1.13% 1.14% For the Years Ended

5 LOAN PORTFOLIO Source: Company documents, as March 31, 2024  Loan growth of 6.9% YOY 23.0% growth in loan interest income YOY  Loan yield of 6.83% 1Q 2024 and 6.12% for 1Q 2023  Loan participation strategy facilitated industry concentration management and efficient use of capital Growth in SBA / USDA guaranteed lending Commercial leases represent 9.2% of the loan portfolio, providing higher yields and shorter average lives than real estate secured loans Oil & Gas related loans made up approximately 2.7% funded and 2.0% unfunded of the total loan portfolio as of March 31, 2024 Hotel and hospitality portfolio totaled $181.4 million, or 6.6% of the total loan portfolio as of March 31, 2024 • All hotels flagged by major brands HIGHLIGHTS Commercial & Industrial10.6% Non-Farm Non- Residential 41.1% Residential Real Estate 22.5% Commercial Leases 9.2% Consumer & Other 1.8% Agriculture & Farm 2.9% C&D 11.9% LOAN PORTFOLIO COMPOSITION 03/31/24 Loan Portfolio Detail ($000s) 2021Y 2022Y 2023Y 1Q2024 Commercial & Industrial $ 398,391 $ 385,279 $ 334,972 $293,292 Non-Farm Non-Residential 886,407 992,929 1,045,865 1,133,516 Residential Real Estate 354,195 486,115 563,771 621,807 Commercial Leases 246,022 317,574 285,415 253,016 Consumer & Other 48,142 47,864 54,485 49,458 Agriculture & Farm 58,557 63,868 73,538 80,956 C&D 174,334 233,091 399,435 328,090 Total Gross Loans $ 2,166,048 $ 2,526,720 $ 2,757,481 $ 2,760,135 LESS: Unearned Income 6,689 7,643 8,773 7,905 Total Loans $ 2,159,359 $ 2,519,077 $ 2,748,708 $ 2,752,230

6 173.36% 122.79% 109.94% 0.00% 20.00% 40.00% 60.00% 80.00% 100.00% 120.00% 140.00% 160.00% 180.00% 200.00% 2022 2023 2024 CREDIT SUMMARY Source: Company documents, as of and for the three months ended March 31, 2024 ACL/NONACCRUALS HISTORICAL ASSET QUALITY 0.47% 1.17% 1.25% 0.18% 0.17% 0.29% 0.00% 0.20% 0.40% 0.60% 0.80% 1.00% 1.20% 1.40% 2022 2023 2024 NPAs/Total Assets NCOs/Average Loans NPAs/TOTAL ASSETS & NCOs/AVG LOANS (dollars in thousands) 12/31/2022 12/31/2023 3/31/2024 NONACCRUAL LOANS $13,566 $25,187 $28,606 90 DAY LOANS AND GREATER BUT STILL ACCRUING $1,142 $15,287 $14,658 OREO $113 $1,250 $1,284 NONPERFORMING ASSETS $14,821 $41,724 $44,548 QTD Loan Chargeoffs $1,007 $3,726 $2,284 YTD Loan Chargeoffs $6,086 $5,771 $2,284 NPAs / TOTAL ASSETS 0.47% 1.17% 1.25% NONACCRUAL LOANS / TOTAL ASSETS 0.43% 0.71% 0.80% ACL / TOTAL LOANS 0.93% 1.13% 1.14% TEXAS RATIO 4.48% 11.63% 12.54%

7 Demand - Noninterest 13.5% Demand - Interest 50.8% Savings 7.5% Time Deposits 28.2% HIGHLIGHTS  Total YoY deposit growth of 7.0%  New Markets opened • Bridgeport, WV Branch opened 4/17/2024 • Mideast market total deposits of approximately $69.1 million with over 1,000 deposit accounts  Long history of ICS / CDARS expertise. $757.2 million at 3/31/24  Uninsured deposits excluding collateralized public funds estimated at approximately 10.0% of deposits  Continued strong CD demand. Time Deposits YoY up 42.4% as consumers shift funds from liquid deposits  Approximately $357 million in CDs mature in 2024. Avg rate of 4.59% DEPOSIT PORTFOLIO Source: Company documents, as of and for the three months ended March 31, 2024 3/31/2024 DEPOSIT MIX ($000) 2021 2022 2023 2024 Demand - Noninterest Bearing $532,578 $524,415 $442,755 $415,113 Demand - Interest Bearing 1,275,544 1,460,259 1,526,628 1,556,257 Savings 201,699 205,760 218,986 229,098 Time Deposits 586,671 533,358 820,725 863,408 Total Deposits $2,596,492 $2,723,792 $3,009,094 $3,063,876 Weighted Average Rate 0.8% 1.2% 3.1% 3.7% Deposit Composition

FIRST GUARANTY BANCSHARES, INC.