Exhibit 99.1

For:			Immediate Release			Contact:			Brett Bauer
			October 23, 2025						574-235-2000

•Net income was $42.30 million for the quarter, up $4.98 million or 13.34% from the previous quarter and up $7.36 million or 21.06% from the third quarter of 2024. Diluted net income per common share was $1.71, up $0.20 or 13.25% from the previous quarter and up $0.30 or 21.28% from the prior year’s third quarter of $1.41. These results include $1.88 million in pre-tax losses from the sale of approximately $73 million of available-for-sale securities executed in the third quarter as well as a $1.00 million charitable contribution to the 1st Source Foundation.

•Return on average assets increased to 1.86% from 1.67% in the previous quarter and 1.59% in the third quarter of 2024. Return on average common shareholders’ equity increased to 13.76% from 12.61% in the previous quarter and 12.87% in the third quarter of 2024.

•A cash dividend increase of two cents per share to $0.40 per common share for the quarter was approved, up 11.11% from the cash dividend declared a year ago.

•Average loans and leases grew $46.93 million in the third quarter, up 0.67% from the previous quarter and increased $409.71 million, up 6.20% from the third quarter of 2024.

•Average deposits increased $75.03 million in the third quarter, up 1.02% from the previous quarter and increased $289.69 million, up 4.06% from the third quarter of 2024.

•Tax-equivalent net interest income was $88.90 million, up $3.56 million or 4.17% from the previous quarter and up $13.27 million, or 17.55% from the third quarter a year ago. Tax-equivalent net interest margin was 4.09%, up eight basis points from the previous quarter and up 45 basis points from the third quarter of 2024.

•Provision for credit losses of $0.90 million was recorded during the quarter compared to $7.69 million in the previous quarter and $1.72 million during the previous year’s third quarter. The allowance for loan and lease losses as a percentage of total loans and leases remained consistent with historical levels, rising to 2.32% at September 30, 2025, up from 2.30% at June 30, 2025, and 2.30% at September 30, 2024.

South Bend, IN - 1st Source Corporation (NASDAQ: SRCE), parent company of 1st Source Bank, today reported record quarterly net income of $42.30 million for the third quarter of 2025, up 13.34% compared to $37.32 million in the previous quarter and up 21.06% from the $34.94 million reported in the third quarter a year ago. Year-to-date 2025 net income was $117.14 million, up 15.76% compared to $101.19 million during the first nine months of 2024. Diluted net income per common share for the third quarter of 2025 was $1.71, up 13.25% compared to $1.51 in the previous quarter and up 21.28% versus $1.41 in the third quarter of 2024. Diluted net income per common share for the first nine months of 2025 was $4.74 compared to $4.09 a year earlier. The quarterly results were impacted by solid growth in net interest income and lower provision for credit losses offset by realized losses from strategic repositioning trades in the investment portfolio and higher noninterest expense.

At its October 2025 meeting, the Board of Directors approved an increase in the cash dividend of two cents per share, raising the approved dividend for the quarter to $0.40 per common share, up 11.11% from the cash dividend declared a year ago. The cash dividend is payable to shareholders of record on November 4, 2025, and will be paid on November 14, 2025.

Andrea G. Short, President and Chief Executive Officer, commented, “We are pleased that we achieved record quarterly net income during the third quarter and continued net interest margin expansion for the seventh consecutive quarter. Higher rates on increased average loan and lease balances, and lower short-term borrowing costs led to an eight basis point improvement in our margin from the prior quarter. The credit quality challenges we experienced during the second quarter improved moderately during the quarter and our nonperforming asset levels decreased. Nonperforming assets to loans and leases at September 30, 2025 was 0.91% down from 1.06% at June 30, 2025 while the allowance for loans and lease losses as a percentage of total loans and leases remained strong at 2.32% up slightly from 2.30% the previous quarter.

“Most importantly, our balance sheet remained resilient throughout the quarter, underscoring a solid financial foundation that has consistently supported our business over time. This strength is not new; it reflects a long-standing commitment to disciplined financial management and positions us well to navigate ongoing macroeconomic uncertainty affecting our customers and their industries. We maintained strong liquidity and upheld our historically conservative capital structure, reinforcing our ability to drive long-term value for shareholders.

“As part of a long-term, multi-year strategy for succession, Christopher J. Murphy III stepped down from his role of Chief Executive Officer of 1st Source Corporation effective October 1, 2025. He now serves as Executive Chairman of 1st Source Corporation and 1st Source Bank. After 50 years of successive leadership as President, Chairman, and Chief Executive Officer, the Bank and Corporation have benefitted greatly from his guidance and expertise. We are pleased that he will continue to serve as Executive Chairman to help position the company for a strong future.

“This change initiated several other role transitions. Kevin C. Murphy, previously Chief Digital Officer and Executive Vice President of 1st Source Corporation and 1st Source Bank, retained his role of Executive Vice President of the Corporation and became President of 1st Source Bank. Additionally, I am honored to have taken on the role of Chief Executive Officer of 1st Source Corporation while also retaining the title of President of 1st Source Corporation and Chief Executive Officer of 1st Source Bank. I look forward to this next stage as we continue to serve our clients and communities well.” Mrs. Short concluded.

Christopher J. Murphy III, Executive Chairman, added, “As Andrea reported, we have had a successful transition of senior leadership and I could not be more excited or optimistic about our future. Andrea has been a 1st Source colleague since 1998 and she has been preparing for this role since 2013. Also, we were very pleased to learn during the third quarter that 1st Source Bank was named to Bank Director Magazine’s Best U.S. Banks list coming in at #19 overall in the top 25 Banks and #8 in the category of $5 billion up to $50 billion in assets.

“Also, in keeping with our commitment to our community, we have remodeled our Elkhart West Banking Center in Indiana, and moved our banking center in Kalamazoo, Michigan to a new location. Both banking centers now feature the Bank’s side-by-side banking model. This experience invites the client behind the “teller line,” allowing for the Bank’s clients and bankers to have a more transparent and inclusive relationship.” Mr. Murphy concluded.

Third quarter average loans and leases were $7.02 billion, which was up $46.93 million or 0.67% from the previous quarter, and increased $409.71 million, up 6.20% from the third quarter a year ago. Year-to-date average loans and leases increased $356.29 million to $6.93 billion, up 5.42% from the first nine months of 2024. Average loan growth from the third quarter of 2024 occurred mainly within the Renewable Energy, Commercial Real Estate, Construction Equipment, Commercial and Agricultural, and Residential Real Estate and Home Equity portfolios.

Third quarter average deposits were $7.42 billion, which was up $75.03 million, or 1.02%, from the previous quarter, and up $289.69 million or 4.06% compared to the quarter ended September 30, 2024. Average deposits for the first nine months of 2025 were $7.37 billion, an increase of $259.42 million, up 3.65% from the same period a year ago. Average deposit balance growth from the third quarter of 2024 was primarily in savings, interest-bearing demand, and non-brokered time deposits offset by decreased brokered deposits.

Third quarter 2025 tax-equivalent net interest income increased $3.56 million to $88.90 million, up 4.17% from the previous quarter and increased $13.27 million, up 17.55% from the third quarter a year ago. For the first nine months of 2025, tax equivalent net interest income increased $33.45 million to $255.33 million, up 15.07% from the same period a year ago.

Third quarter 2025 net interest margin was 4.08%, an increase of eight basis points from the 4.00% in the previous quarter and an increase of 45 basis points from the same period in 2024. On a fully tax-equivalent basis, third quarter 2025 net interest margin was 4.09%, up eight basis points compared to the 4.01% in the previous quarter, and an increase of 45 basis points from the same period in 2024. The increase from the prior quarter and third quarter of 2024 was primarily due to higher rates on increased average loan and lease balances and lower short-term borrowing costs. Higher net interest recoveries contributed three basis points during the third quarter on the net interest margin, compared to no impact during the previous quarter from immaterial net interest charge-offs, while net interest recoveries contributed three basis points in the prior year third quarter.

Net interest margin for the first nine months of 2025 was 3.99%, an increase of 41 basis points compared to 3.58% for the first nine months of 2024. Net interest margin on a fully-tax equivalent basis for the first nine months of 2025 was 4.00%, an increase of 41 basis points compared to 3.59% for the first nine months of the prior year. Net interest recoveries positively contributed three basis points to both the current and previous year-to-date net interest margin.

Third quarter 2025 noninterest income of $21.91 million decreased $1.15 million or 4.99% compared to the previous quarter and decreased $0.54 million or 2.41% compared to the third quarter a year ago. For the first nine months of 2025, noninterest income increased $0.24 million, up 0.36% from the first nine months of 2024.

The decrease from the previous quarter was mainly due to realized losses of $1.88 million in the third quarter compared to $1.00 million in the previous quarter from repositioning of available-for-sale securities. The securities sold during the quarter had a weighted average yield of 0.85% and were replaced with securities having a yield of 3.52%. Additional decreases in the quarter were from lower trust and wealth advisory income from seasonal tax preparation fees during the second quarter, fewer interest rate swap fees, and a decline in bank owned life insurance policy claims recognized. These decreases were offset by a rise in consumer deposit account fees, increased insurance commissions, higher brokerage and commission fees, and increased partnership investment gains.

The decrease in noninterest income compared to the third quarter of 2024 was mainly the result of realized losses from repositioning of available-for-sale securities and reduced equipment rental income as demand for operating leases continued to decline offset by increased partnership investment gains, higher trust and wealth advisory income, increased insurance commissions and deposit account fees.

The increase for the first nine months compared to the same period in 2024 was mainly the result of increased partnership investment gains, higher trust and wealth advisory fees, increased insurance commissions, higher brokerage and commission fees and increased interest rate swap fees. These increases were offset by realized losses on the sale of available-for-sale securities in 2025, lower equipment rental income as demand for operating leases continued to decline, reduced mortgage banking income and a decrease in debit card income.

Third quarter 2025 noninterest expense of $54.78 million increased $2.35 million or 4.47% compared to the prior quarter and increased $3.95 million or 7.77% from the third quarter a year ago. For the first nine months of 2025, noninterest expense increased $10.89 million, up 7.29% from the first nine months of 2024.

The increase in noninterest expense compared to the prior quarter was the result of higher salaries from normal merit increases and higher incentive compensation, a $1.00 million charitable contribution, increased collection and repossession expenses, higher debit card losses, losses on the sale of fixed assets, and increased professional consulting and data processing costs from technology projects, partially offset by decreased furniture and equipment expense and lower leased equipment depreciation.

The increase in noninterest expense compared to the third quarter and first nine months of 2024 was the result of higher salaries and wages from normal merit increases and increased incentive compensation, a $1.00 million charitable contribution, increased data processing costs from technology projects, fewer gains on the sale of fixed assets and off-lease equipment, and increased furniture, equipment and occupancy expenses. These increases were offset by lower leased equipment depreciation and decreased blanket insurance premiums.

The allowance for loan and lease losses decreased to $161.43 million as of September 30, 2025, or 2.32% of total loans and leases primarily as a result of loan and lease runoff and a weakened forward economic outlook with increased uncertainty. This 2.32% is an increase compared to 2.30% at June 30, 2025, and 2.30% at September 30, 2024 due to a weakened forward economic outlook with increased uncertainty. Net charge-offs of $1.88 million were recorded for the third quarter of 2025, compared with net charge-offs of $1.87 million in the prior quarter and net charge-offs of $0.85 million in the same quarter a year ago.

The provision for credit losses was $0.90 million for the third quarter of 2025, a decrease of $6.79 million from the previous quarter and a decrease of $0.83 million compared with the same period in 2024. The decrease in the provision expense compared to the prior quarter was primarily due to a decline in loan and lease outstandings, a decrease in nonaccrual loans and leases, and specific impairments, offset by an increase in the provision for unfunded commitments. The ratio of nonperforming assets to loans and leases was 0.91% as of September 30, 2025, compared to 1.06% on June 30, 2025, and 0.47% on September 30, 2024. The decrease in nonperforming assets during the quarter was primarily from lower nonaccrual loans and leases and repossessions.

As of September 30, 2025, the common equity-to-assets ratio was 13.65%, compared to 13.19% at June 30, 2025, and 12.60% a year ago. The tangible common equity-to-tangible assets ratio was 12.85% at September 30, 2025, compared to 12.38% at June 30, 2025, and 11.76% a year earlier. The Common Equity Tier 1 ratio, calculated under banking regulatory guidelines, was 15.18% at September 30, 2025, compared to 14.60% at June 30, 2025, and 14.18% a year ago.

Capital accretion over the last twelve months has been driven primarily by growth in retained earnings and a reduction in unrealized losses in our short-duration investment securities available-for-sale portfolio.

During the third quarter of 2025, 105,381 shares were repurchased for treasury reducing common shareholders’ equity by $6.38 million. Total year-to-date repurchased shares of 160,363 have reduced common shareholder’s equity by $9.68 million.

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, 18 1st Source Bank Specialty Finance Group locations nationwide, nine Wealth Advisory Services locations, 10 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,” “hope,” “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 with 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.

# # #

(charts attached)

(1) See “Reconciliation of Non-GAAP Financial Measures” for more information on this performance measure/ratio.

(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