Two ships of the Royal Navy have borne the name HMS Otus:

• HMS Otus (N92) was an Odin-class submarine launched in 1928. After service in Hong Kong during WW2 she was transferred to Durban in 1943 as a training vessel. She was sold in 1946 and her hull was scuttled off Durban that year. Her wreck has since been rediscovered (2013) in deep but diveable waters some 8 km (5.0 mi) from Durban harbour and is currently offered as a specialist deep wreck dive.
• HMS Otus (S18) was an Oberon-class submarine launched in 1962. She was paid off in 1991, and sold in 1992. She became a museum ship in 2002.