Two ships of the Royal Navy have been named HMS Madagascar after the island of Madagascar off the coast of Africa:
was 38-gun fifth rate formerly the French ship Nereide. She was captured in 1811 and was broken up in 1819. was a 46-gun fifth rate launched in 1822. She was placed on harbour service from 1853 and was sold in 1863.
See also served as a transport during the First Opium War but was NOT part of the British Navy; she was burnt by accident in September 1841. List of ships named Madagascar