HMS Ulster (R83) was a U-class destroyer of the British Royal Navy that saw service during World War II. She was later converted into a Type 15 fast anti-submarine frigate, with the new pennant number F83. HMS Ulster would be the third vessel in Royal Navy history to have that name. With money's gathered through a Naval Savings Campaign in 1942 known as Warship Week, the ship was adopted by the civil community of Ulster's County Down.