HMS Andrew (P423/S23/S63), was an Amphion-class submarine of the Royal Navy, built by Vickers Armstrong and launched on 6 April 1946.

The submarine was fitted with a 4-inch (102 mm) deck gun in 1964 for service during the Indonesia–Malaysia confrontation to counter blockade-running junks.

[4] Andrew was fitted with ten 21 inches (530 mm) torpedo tubes, one QF 4 inch naval gun Mk XXIII, one Oerlikon 20 mm cannon, and a .303 British Vickers machine gun.

[4] In September 1950 Andrew sailed to Canada for a three-month deployment training with the Royal Canadian Navy.

[6] In February 1953, Andrew deployed to Bermuda for training with the Royal Canadian Navy cruiser Quebec, destroyer Huron and minesweeper Portage.