[Form 4] OMNICOM GROUP INC. Insider Trading Activity

Rhea-AI Filing Summary

Cassandra Santos, a director of Omnicom Group Inc. (OMC), reported a non-derivative acquisition of 628.6 shares of Omnicom common stock on 10/01/2025 under a transaction coded A. The filing states she elected to defer receipt of these shares under the Omnicom Group Inc. 2021 Incentive Award Plan. Following the reported transaction(s), the reporting person beneficially owned 4,478.02 shares as of 10/03/2025. The transaction was reported on Form 4 and signed on behalf of Ms. Santos by an attorney-in-fact, Eric J. Cleary, on 10/03/2025. The reported acquisition carried a price of $0, reflecting the deferral election rather than a cash purchase.

Positive

• Director retained equity exposure by deferring compensation into 628.6 shares
• Beneficial ownership increased to 4,478.02 shares as of 10/03/2025

Negative

• No cash purchase; transaction reported with a price of $0, indicating no immediate market investment
• Fractional-share reporting (e.g., 628.6) may reflect plan accounting, reducing clarity on whole-share economic impact

Insights

Corporate Governance Specialist

Director deferred equity award; ownership increased to 4,478.02 shares.

The Form 4 discloses a non-cash acquisition of 628.6 shares under the company's 2021 Incentive Award Plan due to an election to defer receipt. This is a common mechanism for directors to defer compensation into equity rather than receive immediate shares or cash.

The filing was executed by an attorney-in-fact on 10/03/2025, and shows a post-transaction beneficial ownership of 4,478.02 shares. Because the transaction was recorded with a price of $0, it reflects a plan election rather than an open-market purchase or sale.

Insider Transactions Analyst

Transaction is routine and non‑market-moving based on disclosed facts.

The report indicates an award deferral (transaction code A) rather than a purchase or sale; no cash consideration was reported. The fractional share amounts (628.6 acquired; 4,478.02 held) are consistent with plan allocations or pro rata calculations.

There are no disclosed sales, option exercises, or derivative activities in this filing that would materially change outstanding exposure beyond the stated beneficial ownership.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

Santos Cassandra

(Last) (First) (Middle)

C/O OMNICOM GROUP INC.

280 PARK AVENUE

(Street)

NEW YORK NY 10017

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
OMNICOM GROUP INC. [ OMC ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
10/01/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock, par value $0.15 per share	10/01/2025		A		628.6(1)	A	$0	4,478.02(2)	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. The reporting person elected to defer receipt of these shares under the terms of the Omnicom Group Inc. 2021 Incentive Award Plan.

2. 10/03/25

	/s/ Eric J. Cleary, Attorney in Fact for Cassandra Santos	10/03/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did Cassandra Santos report on Form 4 for OMC?

She reported acquisition of 628.6 shares under the Omnicom Group Inc. 2021 Incentive Award Plan, with post-transaction beneficial ownership of 4,478.02 shares.

When was the transaction dated and when was it reported?

The transaction date is 10/01/2025 and the Form 4 was signed/reported on 10/03/2025.

Was this a market purchase or a deferred award?

The filing states the reporting person elected to defer receipt of the shares under the company plan, and the reported price is $0, indicating a deferral rather than a cash market purchase.

Who signed the Form 4 filing?

The Form 4 was signed by Eric J. Cleary, Attorney in Fact, for Cassandra Santos on 10/03/2025.

Does the filing show any derivative or option transactions?

No. Table II (derivative securities) shows no entries; only a non-derivative acquisition is reported.