Omnicom Group Inc.

Item 2.02. Results of Operations and Financial Condition. On April 28, 2026, Omnicom Group Inc. ("Omnicom,"the"Company," "we," "our"or"us") published an earnings release reporting its financial results for the three months ended March 31, 2026. 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 April 28, 2026, Omnicom hosted an earnings call and posted on its website a related investor presentation in connection with publishing its financial results for the three months ended March 31, 2026. 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, as amended. In addition, from time to time, we or our representatives have made, or may make, forward-looking statements, orally or in writing. These statements, other than statements of historical fact, 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 our management as well as assumptions made by, and information currently available to, our 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 our 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 completed merger (the "Merger") between us and The Interpublic Group of Companies, Inc. ("IPG"), including risks related to the integration of IPG's business, such as, among others: uncertainties associated with retaining key management and other employees; potential disruptions to client, vendor, and business partner relationships; the risk that integration activities may be more time-consuming, complex, or costly than expected; the possibility that anticipated synergies, efficiencies, and other benefits of the Merger may not be realized, or may be realized more slowly than anticipated; and risks associated with managing a larger, more complex combined organization and effectively integrating systems, processes, operations, and cultures; • adverse economic conditions, 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 our 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; • failure to manage potential conflicts of interest between or among clients; • unanticipated changes related to competitive factors in the marketing and communications services industries; • unanticipated changes to, or an inability to hire and retain, key personnel; • currency exchange rate fluctuations; • reliance on information technology systems and risks related to cybersecurity incidents; • effective management of the risks, challenges and efficiencies presented by utilizing artificial intelligence, or AI, technologies and related partnerships in our business, and their use by our competitors; • failure to adapt to technological developments; • our liquidity, long-term financing needs, credit ratings and access to capital markets;

Exhibit Number Description 99.1 Earnings release dated April 28, 2026. 99.2 Investor presentation materials dated April 28, 2026.

104 The cover page from this Current Report on Form 8-K, formatted in Inline XBRL