John Christopher Aquilino is a retired United States Navy admiral who last served as the commander of United States Indo-Pacific Command from 2021 to 2024. He previously served as the commander of the United States Pacific Fleet and before that, commander of the United States Fifth Fleet and Combined Maritime Forces.

The Fifth Fleet is a numbered fleet of the United States Navy. Its area of responsibility encompasses approximately 2.5 million square miles, and includes the Persian Gulf, Red Sea, Arabian Sea, and parts of the Indian Ocean. It shares a commander and headquarters with U.S. Naval Forces Central Command (NAVCENT) in Bahrain. Fifth Fleet/NAVCENT is a component command of, and reports to, U.S. Central Command (CENTCOM).