HMS Vigilant was a merchantman converted into a warship during the American Revolution. After serving as a transport in North American waters from 1775, she was purchased by the Royal Navy (RN) and modified for shore bombardment duties in 1777. She was instrumental in the eventual British success during the siege of Fort Mifflin that same year and supported British operations in Georgia and South Carolina in 1779–80. Her heavy armament proved to be more than Vigilant was designed to handle and she was condemned and disposed of in 1780.