Prohibiting Certain Off-Post Demonstrations Act of 2024 This bill prohibits members of the Armed Forces from participating in off-post demonstrations under certain circumstances. The bill makes violations of the prohibition punishable under the Uniform Code of Military Justice. Under the bill, members are prohibited from participating in off-post demonstrations when they are on-duty, they are in a foreign country, the activities constitute a breach of law and order, violence is likely to result, they are in uniform against regulations, the demonstration is against U.S. military action, the demonstration is against U.S. support of a U.S. ally at war, or the demonstration is outside of the embassy of the United States or a U.S. ally.