A motor launch (ML) is a small military vessel in Royal Navy service.

Similar vessels were used by the Royal Air Force for armed high-speed air-sea rescue.

These were five hundred and eighty 80-foot-long (24 m) vessels built by the US Elco company for the Admiralty, receiving the numbers ML-1 to ML-580.

They served with the Royal Navy between 1916 and the end of the war, defending the British coast from German submarines.

[2] The only known surviving example of a World War I era motor launch is ML-286, which now lies in a poor condition on the banks of the River Thames.