Six ships of the Royal Navy have borne the name HMS Cossack, after the Cossack people of Eastern Europe, whilst another was planned, but was cancelled:
HMS Cossack was previously HMS Pandour, a 22-gun sixth ratefrigate renamed and launched in 1806. She was broken up in 1816.
HMS Cossack was to have been a steam gunvessel, laid down at Portsmouth Dockyard in 1846, but cancelled in 1849.
HMS Cossack was previously the Russian ship Witjas, a wood screw corvette captured in 1854 and sold in 1875.
HMS Cossack was a torpedo cruiser launched in 1886 and sold in 1905.
HMS Cossack was a Tribal-class destroyer launched in 1937 and sunk four days after being torpedoed by the German submarineU-563 in 1941, when attempts to tow her to safety failed.
HMS Cossack was a C class destroyer launched in 1944 and broken up in 1961.