The Mark 54 Lightweight Hybrid Torpedo (LHT) is an anti-submarine warfare (ASW) torpedo used by the Royal Australian Navy. It is air-dropped by the Navy's MH-60R Seahawk Helicopters as well as the RAAF’s P-8A Poseidon Maritime Patrol Aircraft.

Function Lightweight torpedo
Manufacturer Raytheon Systems
Designed 1999
Guidance Active or passive/active acoustic homing
Power plant Reciprocating external combustion (Otto II liquid fuel)
Weight 276 kilograms
Diameter 324 mm
Length 2.72 metres
Speed 74.1 kilometres per hour