Strategy To Oppose Purposeful CCP Aggression at the United Nations Act of 2023 or the STOP CCP at UN Act of 2023 This bill requires actions to address efforts by China to expand its influence on the United Nations. Specifically, the bill requires the Department of State to establish the Office of Multilateral Strategy, which must implement a strategy to counter China at the United Nations. The office must report on its work to Congress. The State Department must also increase the number of U.S.-sponsored junior professional officers at the United Nations to match or exceed the number of such officers sponsored by China. Furthermore, the State Department and the U.S. Permanent Representative to the United Nations must report to Congress annually about China's actions to expand its influence on the United Nations, including through coercion, intimidation, and other illegitimate means.