Omnicom Group Inc.

Item 2.02. Results of Operations and Financial Condition. On October 21, 2025, Omnicom Group Inc. ("Omnicom"or the"Company") published an earnings release reporting its financial results for the three and nine months ended September 30, 2025. A copy of the earnings release is furnished as Exhibit 99.1 to this report and is incorporated by reference herein in its entirety. Item 7.01. Regulation FD Disclosure. On October 21, 2025, Omnicom hosted an earnings call and posted on its website a related investor presentation in connection with publishing its financial results for the three and nine months ended September 30, 2025. A copy of the presentation is furnished as Exhibit 99.2 to this report and is incorporated by reference herein in its entirety. The information under Items 2.02 and 7.01 above (including Exhibits 99.1 and 99.2 hereto) is being furnished and shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such filing. Forward-Looking Statements. Certain statements in the exhibits to this Current Report on Form 8-K contain forward-looking statements, including statements within the meaning of the Private Securities Litigation Reform Act of 1995. In addition, from time to time, the Company or its representatives have made, or may make, forward-looking statements, orally or in writing. These statements may discuss goals, intentions and expectations as to future plans, trends, events, results of operations or financial condition, or otherwise, based on current beliefs of the Company's management as well as assumptions made by, and information currently available to, the Company's management. Forward-looking statements may be accompanied by words such as "aim," "anticipate," "believe," "plan," "could," "should," "would," "estimate," "expect," "forecast," "future," "guidance," "intend," "may," "will," "possible," "potential," "predict," "project" or similar words, phrases or expressions. These forward-looking statements are subject to various risks and uncertainties, many of which are outside the Company's control. Therefore, you should not place undue reliance on such statements. Factors that could cause actual results to differ materially from those in the forward-looking statements include: • risks relating to the pending merger with The Interpublic Group of Companies, Inc., or IPG, including: that the merger may not be completed in a timely manner or at all; delays, unanticipated costs or restrictions resulting from regulatory review of the merger, including the risk that Omnicom or IPG may be unable to obtain governmental and regulatory approvals required for the merger, or that such approvals may result in the imposition of conditions that could adversely affect the combined company or the expected benefits of the merger; uncertainties associated with the merger may cause a loss of both companies' management personnel and other key employees, and cause disruptions to both companies' business relationships; the merger agreement subjects the Company and IPG to restrictions on business activities prior to the effective time of the merger; the Company and IPG are expected to incur significant costs in connection with the merger and integration; litigation risks relating to the merger; the business and operations of both companies may not be integrated successfully in the expected time frame; the merger may result in a loss of both companies' clients, service providers, vendors, joint venture participants and other business counterparties; and the combined company may fail to realize all of the anticipated benefits of the merger or fail to effectively manage its expanded operations; • adverse economic conditions and disruptions, including geopolitical events, international hostilities, acts of terrorism, public health crises, inflation or stagflation, tariffs and other trade barriers, central bank interest rate policies in countries that comprise our major markets, labor and supply chain issues affecting the distribution of our clients' products, or a disruption in the credit markets; • international, national or local economic conditions that could adversely affect the Company or its clients; • losses on media purchases and production costs incurred on behalf of clients; • reductions in client spending, a slowdown in client payments or a deterioration or disruption in the credit markets; • the ability to attract new clients and retain existing clients in the manner anticipated; • changes in client marketing and communications services requirements;

Exhibit Number Description 99.1 Earnings release dated October 21, 2025. 99.2 Investor presentation materials dated October 21, 2025. 104 The cover page from this Current Report on Form 8-K, formatted in Inline XBRL