USS Fly was an eight-gun sloop of war built into the Continental Navy. She was part of a squadron that raided the port of Nassau and engaged the 20-gun HMS Glasgow. Fly, one of the eight former merchant ships fitted out by the Naval Committee between November 1775 and January 1776, was purchased in Baltimore, Maryland under Congressional authorization of a small tender or despatch vessel for the fleet. A schooner, often referred to as a sloop, she was first commanded by Lieutenant Hoystead Hacker.