Exhibit 99.1

•Net income was a record $158.28 million for the year of 2025, up 19.34% from 2024 and was $41.14 million for the fourth quarter of 2025, down 2.73% from the previous quarter and up 30.87% from the fourth quarter of 2024. Diluted net income per common share was $6.41 for the year of 2025, up 19.59% from 2024 and was $1.67 for the fourth quarter of 2025, down 2.34% from the previous quarter and up 31.50% from the prior year’s fourth quarter. These results include $5.81 million and $8.68 million in pre-tax losses during the fourth quarter and full year, respectively, from repositioning of available-for-sale securities.

•Return on average assets increased to 1.76% and return on average common shareholders’ equity increased to 13.16% for the full year 2025 from 1.52% and 12.54%, respectively, in 2024. For the fourth quarter of 2025, return on average assets increased to 1.80% and return on average common shareholders’ equity increased to 12.94% from 1.42% and 11.21%, respectively, in the fourth quarter of 2024.

•Cash dividend of $0.40 per common share was approved, up 11.11% from the cash dividend declared a year ago.

•Average loans and leases grew $336.29 million, up 5.10% during 2025 to $6.93 billion from $6.60 billion in 2024.

•Average deposits increased $263.33 million, up 3.70% to $7.38 billion during 2025 from $7.12 billion in 2024. Average deposits, net of brokered deposits, increased $338.84 million, up 5.18% to $6.88 billion during 2025 from $6.54 billion in 2024.

•Tax-equivalent net interest margin was 4.07% for 2025, up 43 basis points from 2024 and was 4.29% for the fourth quarter of 2025, up 20 basis points from the prior quarter and up 51 basis points from the fourth quarter of 2024. Net interest recoveries had a positive 14 basis point impact on the fourth quarter 2025 tax-equivalent net interest margin compared to a positive three basis point impact during the previous quarter and the fourth quarter of 2024.

South Bend, IN — 1st Source Corporation (NASDAQ: SRCE), parent company of 1st Source Bank, today reported record net income of $158.28 million for 2025, an increase of 19.34% compared to $132.62 million earned in 2024. Fourth quarter net income was $41.14 million, an increase of 30.87% compared to $31.44 million earned in the fourth quarter of 2024. Diluted net income per common share for the year was a record $6.41, up 19.59% from the $5.36 earned a year earlier. Diluted net income per common share for the fourth quarter was $1.67, up 31.50% from the $1.27 earned in the fourth quarter of the previous year.

Return on average assets increased to 1.76% and return on average common shareholders’ equity increased to 13.16% for the full year 2025 from 1.52% and 12.54%, respectively, in 2024. For the fourth quarter of 2025, return on average assets increased to 1.80% and return on average common shareholders’ equity increased to 12.94% from 1.42% and 11.21%, respectively, in the fourth quarter of 2024. The increase in both ratios was mainly due to a larger percentage increase in net income compared to the percent increase in average assets and average common shareholders’ equity for both periods presented.

At its January 2026 meeting, the Board of Directors approved a cash dividend of $0.40 per common share, up 11.11% from the $0.36 per common share declared a year ago. The cash dividend is payable to shareholders of record on February 3, 2026, and will be paid on February 13, 2026.

Andrea G. Short, President and Chief Executive Officer, commented, “We are pleased to announce record net income for the fifth year in a row and we reached our 38th consecutive year of dividend growth. We were able to grow average loans and leases by $336.29 million or 5.10% and average deposits, net of brokered deposits, increased by $338.84 million or 5.18% from 2024. Higher rates on investment securities, relatively stable rates on loans and leases, and lower deposit and short-term borrowing rates resulted in tax-equivalent net interest margin expansion during 2025 to 4.07% from 3.64% in 2024. During the fourth quarter, we also experienced margin expansion of 20 basis points. Net interest recoveries had a positive 14 basis point impact on the fourth quarter 2025 tax-equivalent net interest margin compared to a positive three basis point impact during the previous quarter. We had net charge-offs to average loans and leases of 0.06% in 2025 compared to 0.09% in 2024. These positive income statement results were supported by a strong balance sheet. During the year, we maintained strong liquidity and upheld our historically conservative capital structure. I am extremely proud that my colleagues were able to achieve such positive results despite the unique challenges of the last several years.

“We were also delighted to learn that Chris Murphy, our Executive Chairman was honored with a 2025 Leaders in Banking Excellence Award by the Indiana Bankers Association. These awards showcase exceptional individuals who have positively impacted Indiana banks and the communities they serve. Chris’ contributions over the past 50-plus years have helped shape the Indiana banking community. He is a passionate advocate for our clients, our communities, and community banks and is a true example of what it means to be a servant leader.

“Finally, in the fourth quarter, we rolled out a new platform called Online & Mobile Banking for Business. This new suite of services allows small business owners a fast, reliable, and convenient way to manage their business accounts online. It gives them new tools to help them simplify payments, create team account access for their employees, and manage their cashflow more quickly and easily with no manual data entry. This new platform is one more way we are showing our commitment to supporting small businesses in the communities where we live and serve.” Ms. Short concluded.

Christopher J. Murphy III, Executive Chairman, added, “During the fourth quarter of 2025, we were very pleased to learn that we are in rare company to be named among Piper Sandler’s Sm-All Stars for the third year in a row. The list identifies the top performing small-cap banks and thrifts in the country. To earn this prestigious status, companies need to have a market cap below $2.5 billion and meet a range of criteria related to growth, profitability, credit quality, and capital strength.

Additionally, we were pleased to learn that 1st Source once again received a “Superior” Bauer 5-Star Rating, the highest rating by BauerFinancial. The ratings are based on several factors including capital ratio, profitability/loss trend, evaluation of the level of delinquent loans, repossessed assets, the market versus book value of the investment portfolio, the community reinvestment rating (CRA), liquidity and more.” Mr. Murphy concluded.

Annual average loans and leases of $6.93 billion increased $336.29 million, up 5.10% from the full year 2024. Quarterly average loans and leases of $6.95 billion increased $276.67 million, up 4.14% in the fourth quarter of 2025 from the year ago quarter and have decreased $62.30 million, down 0.89% from the third quarter of this year. Strong growth primarily within our Renewable Energy, Commercial Real Estate, Construction Equipment and Residential Real Estate and Home Equity portfolios drove total average loans and leases higher during the year offset by a reduction in the Auto and Light Truck portfolio mainly due to auto rental clients downsizing their fleets during the year.

Annual average deposits for 2025 were $7.38 billion, an increase of $263.33 million, up 3.70% from 2024. Quarterly average deposits of $7.42 billion grew $274.86 million, up 3.85% compared to the same quarter last year and were relatively flat compared to the third quarter of this year. Growth over the last year came from non-brokered time deposits, money market accounts, and interest-bearing demand deposits offset by a decrease in more expensive brokered deposits. Average brokered deposits decreased $75.50 million or 13.00% during the full year and decreased $162.09 million or 29.77% during the fourth quarter. At December 31, 2025, the composition of our deposit portfolio continued to reflect a well-balanced, high quality mix across our deposit categories. Core deposits represented 91.07% of total deposits and noninterest-bearing demand deposits represented 22.15% of total deposits at year-end 2025.

For full year 2025, tax-equivalent net interest income was $348.79 million, an increase of $47.38 million, up 15.72% compared to the full year 2024. Fourth quarter 2025 tax-equivalent net interest income of $93.45 million increased $13.94 million, up 17.53% from the fourth quarter a year ago and increased $4.55 million, up 5.12% from the third quarter.

Net interest margin for the year ending December 31, 2025 was 4.07%, an increase of 44 basis points from the 3.63% for the year ending December 31, 2024. Net interest margin on a tax-equivalent basis for the year ending December 31, 2025 was 4.07%, an increase of 43 basis points from the 3.64% for the year ending December 31, 2024. Net interest recoveries positively contributed six basis points to the 2025 tax-equivalent net interest margin compared to a positive three basis point impact during 2024.

Fourth quarter 2025 net interest margin was 4.28%, an increase of 51 basis points from the 3.77% for the same period in 2024 and an increase of 20 basis points from the prior quarter. Fourth quarter 2025 net interest margin on a fully tax-equivalent basis was also 4.29%, an increase of 51 basis points from the 3.78% for the same period in 2024 and an increase of 20 basis points from the 4.09% in the prior quarter. Net interest recoveries had a positive 14 basis point impact on the fourth quarter 2025 tax-equivalent net interest margin compared to a positive three basis point impact during the fourth quarter of 2024.

Noninterest income for the twelve months ended December 31, 2025 was $85.60 million, down $0.70 million or 0.82% compared to the twelve months ended December 31, 2024. Fourth quarter 2025 noninterest income of $17.54 million decreased $0.95 million, or 5.11% from the fourth quarter a year ago and decreased $4.37 million or 19.94% from the third quarter.

Noninterest income during the twelve months ended December 31, 2025 was lower compared to a year ago mainly from realized losses of $8.68 million from repositioning available-for-sale investment securities compared to realized losses of $3.90 million during 2024. The securities sold during 2025 had a weighted average yield of 0.92% and were replaced with securities having a weighted average yield of 3.66%. The cumulative breakeven on these transactions is estimated to be approximately 1.5 years. Additionally, noninterest income decreased from lower equipment rental income due to a decrease in the equipment rental portfolio as demand for operating leases continues to decline. These decreases were offset by higher partnership investment gains related to the sale of renewable energy tax equity investments, increased trust and wealth advisory income primarily from increased assets under management during the year, a rise in insurance commissions including contingent commissions, and growth in interest rate swap fees.

The decrease in noninterest income from the previous quarter was mainly due to higher losses from repositioning available-for-sale securities. The securities sold during the quarter had a weighted average yield of 0.91% and were replaced with securities having a weighted average yield of 3.64%. The breakeven on this transaction is estimated to be approximately 1.7 years. Additionally, we had a write-down of $0.77 million on a small business capital investment during the fourth quarter. These decreases were offset by increased trust and wealth advisory income primarily from estate fees and positive market performance during the quarter.

Noninterest expense for the twelve months ended December 31, 2025 was $216.84 million, an increase of $13.24 million, or 6.50% compared to the same period a year ago. Fourth quarter 2025 noninterest expense of $56.56 million increased $2.35 million, or 4.33% from the fourth quarter a year ago and increased $1.78 million or 3.25% from the prior quarter.

The increase in noninterest expense for 2025 from 2024 was primarily due to higher salaries and benefits which included higher base salaries as a result of normal merit increases, a rise in incentive compensation and group insurance claims, as well as higher company contributions to employee retirement accounts due to the utilization of accumulated plan forfeitures of $0.65 million during 2024. Also contributing to higher noninterest expense was increased data processing costs related to technology projects and $1.10 million in charitable contributions. These increases were offset by lower leased equipment depreciation and decreased insurance premiums.

The increase in noninterest expense from the previous quarter was mainly due to higher salaries and wages from normal merit increases and increased incentive compensation, as well as higher group insurance claims, and increased professional fees. These increases were offset by fewer charitable contributions and lower debit card loss activity.

The allowance for loan and lease losses as of December 31, 2025 was 2.30% of total loans and leases compared to 2.32% at September 30, 2025, and 2.27% at December 31, 2024.

Net charge-offs for the full year of 2025 were $4.21 million compared to net charge-offs of $5.68 million in 2024. This resulted in net charge-offs to average loans and leases of 0.06% for 2025 compared to net charge-offs of 0.09% for 2024. Net charge-offs in the fourth quarter of 2025 were $0.28 million compared with net charge-offs of $0.69 million in the same quarter a year ago and $1.88 million of net charge-offs in the previous quarter.

The provision for credit losses was $12.56 million for the twelve months ended December 31, 2025, and included $0.71 million for the fourth quarter of 2025, an increase of $0.10 million and a decrease of $2.87 million, respectively, compared with the same periods in 2024. The ratio of nonperforming assets to loans and leases was 1.10% as of December 31, 2025, compared to 0.91% on September 30, 2025 and 0.46% on December 31, 2024. Nonperforming assets increased $14.19 million during the fourth quarter primarily due to the addition of one auto rental client, with whom we are actively engaged and pursuing resolution strategies.

As of December 31, 2025, the common equity-to-assets ratio was 14.08%, compared to 13.65% at September 30, 2025 and 12.44% a year ago. The tangible common equity-to-tangible assets ratio was 13.28% at December 31, 2025 compared to 12.85% at September 30, 2025 and 11.61% a year earlier. The Common Equity Tier 1 ratio, calculated under banking regulatory guidelines, was 15.52% at December 31, 2025 compared to 15.18% at September 30, 2025 and 14.21% a year ago.

During the fourth quarter and full year of 2025, 69,673 shares and 230,036 shares were repurchased for treasury reducing common shareholders’ equity by $4.19 million and $13.87 million, respectively.

1st Source common stock is traded on the NASDAQ Global Select Market under “SRCE” and appears in the National Market System tables in many daily newspapers under the code name “1st Src.” Since 1863, 1st Source has been committed to the success of its clients, individuals, businesses and the communities it serves. For more information, visit www.1stsource.com.

1st Source serves the northern half of Indiana and southwest Michigan and is the largest locally controlled financial institution headquartered in the area. While delivering a comprehensive range of consumer and commercial banking services through its community bank offices, 1st Source has distinguished itself with highly personalized services. 1st Source Bank also competes for business nationally by offering specialized financing services for new and used private and cargo aircraft, automobiles for leasing and rental agencies, medium and heavy duty trucks, and construction equipment. The Corporation includes 78 banking centers, 16 1st Source Bank Specialty Finance Group locations nationwide, nine Wealth Advisory Services locations, 13 1st Source Insurance offices, and three loan production offices.

Except for historical information contained herein, the matters discussed in this document express “forward-looking statements.” Generally, the words “believe,” “contemplate,” “seek,” “plan,” “possible,” “assume,” “expect,” “intend,” “targeted,” “continue,” “remain,” “estimate,” “anticipate,” “project,” “will,” “should,” “indicate,” “would,” “may” and similar expressions indicate forward-looking statements. Those statements, including statements, projections, estimates or assumptions concerning future events or performance, and other statements that are other than statements of historical fact, are subject to material risks and uncertainties. 1st Source cautions readers not to place undue reliance on any forward-looking statements, which speak only as of the date made.

1st Source may make other written or oral forward-looking statements from time to time. Readers are advised that various important factors could cause 1st Source’s actual results or circumstances for future periods to differ materially from those anticipated or projected in such forward-looking statements. Such factors, among others, include changes in laws, regulations or accounting principles generally accepted in the United States; 1st Source’s competitive position within its markets served; increasing consolidation within the banking industry; unforeseen changes in interest rates; unforeseen downturns in the local, regional or national economies or in the industries in which 1st Source has credit concentrations; and other risks discussed in 1st Source’s filings with the Securities and Exchange Commission, including its Annual Report on Form 10-K, which filings are available from the SEC. 1st Source undertakes no obligation to publicly update or revise any forward-looking statements.

The accounting and reporting policies of 1st Source conform to generally accepted accounting principles (“GAAP”) in the United States and prevailing practices in the banking industry. However, certain non-GAAP performance measures are used by management to evaluate and measure the Company’s performance. Although these non-GAAP financial measures are frequently used by investors to evaluate a financial institution, they have limitations as analytical tools, and should not be considered in isolation, or as a substitute for analyses of results as reported under GAAP. These include taxable-equivalent net interest income (including its individual components), net interest margin (including its individual components), the efficiency ratio, tangible common equity-to-tangible assets ratio and tangible book value per common share. Management believes that these measures provide users of the Company’s financial information a more meaningful view of the performance of the interest-earning assets and interest-bearing liabilities and of the Company’s operating efficiency. Other financial holding companies may define or calculate these measures differently.

Management reviews yields on certain asset categories and the net interest margin of the Company and its banking subsidiaries on a fully taxable-equivalent (“FTE”) basis. In this non-GAAP presentation, net interest income is adjusted to reflect tax-exempt interest income on an equivalent before-tax basis. This measure ensures comparability of net interest income arising from both taxable and tax-exempt sources. Net interest income on a FTE basis is also used in the calculation of the Company’s efficiency ratio. The efficiency ratio, which is calculated by dividing non-interest expense by total taxable-equivalent net revenue (less securities gains or losses and lease depreciation), measures how much it costs to produce one dollar of revenue. Securities gains or losses and lease depreciation are excluded from this calculation to better match revenue from daily operations to operational expenses. Management considers the tangible common equity-to-tangible assets ratio and tangible book value per common share as useful measurements of the Company’s equity.

See the table marked “Reconciliation of Non-GAAP Financial Measures” for a reconciliation of certain non-GAAP financial measures used by the Company with their most closely related GAAP measures.

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(2) Calculated as common shareholders’ equity divided by common shares outstanding at the end of the period.

(3) Calculated under banking regulatory guidelines.

The NASDAQ Stock Market National Market Symbol: “SRCE” (CUSIP #336901 10 3)

Please contact us at shareholder@1stsource.com