Launch is a name given to several different types of boat. The wide range of usage of the name extends from utilitarian craft through to pleasure boats built to a very high standard.

In naval use, the launch was introduced as a ship's boat towards the end of the 17th century. On each warship, the launch was usually the largest boat out of those carried aboard. It could be propelled by oar or sail, with this type remaining in service into the 20th century. Steam launches were introduced on a trial basis in 1867, but as steam-powered ship's boats became more common, the majority were steam pinnaces.

Other military examples were the various motor launches used in the 20th century, employed for harbour defence, anti-submarine patrols, escorting coastal convoys, minesweeping and recovering aircrew from crashed aircraft. Generally, these were decked boats, some of which were capable of fast speeds.

A powered boat operated by a regulatory or official organisation may be termed a launch – such as the police launch or a harbour-master's launch. The size range and capabilities vary according to the precise role.

In private use, a launch is invariably a powered boat, using a steam, electric, petrol or diesel engine. Some are built to a very high standard of finish, with large amounts of varnished hardwood and polished fittings. Various local historic types are kept in use by enthusiasts and museums.