This bill provides FY2024 supplemental appropriations to the Department of Defense (DOD) for assistance to Ukraine and establishes the Office of the Special Inspector General for Ukraine Assistance. Specifically, the bill provides appropriations to DOD for the Ukraine Security Assistance Initiative. The funding is provided for purposes such as providing assistance and equipment to the military and national security forces of Ukraine and other forces or groups engaged in resisting Russian aggression against Ukraine, replacing weapons or defense articles provided to Ukraine from the U.S. inventory, and recovering or disposing of equipment procured using funds provided by this bill or prior acts. The bill also establishes and provides funding for the Office of the Special Inspector General for Ukraine Assistance. The duties of the office include conducting and supervising audits and investigations related to the programs and operations funded with appropriations provided to support Ukraine; coordinating and making recommendations regarding policies designed to prevent and detect waste, fraud, and abuse; and keeping the Department of State, DOD, and Congress informed about problems, deficiencies, and the need for corrective actions.