The 51st Battalion, Far North Queensland Regiment (51 FNQR) is an Australian Army Reserve Regional Force Surveillance Unit headquartered at Porton Barracks in Cairns.

Its area of operations includes the Torres Strait (especially Australia's border with Papua New Guinea) and the Cape York littoral environment.

Additional tasks for 51FNQR include the collection and collation of military geographic information as well as community engagement and disaster relief operations.

Soldiers in the unit are cross-trained in a variety of "low-visibility" skills such as weapons, survival, sniping, medic, small boat handling, driving, tracking, air operations.

[2] The unit's first intake of personnel were drawn from men originating from Western Australia, many of whom had already served with the 11th Battalion during the fighting in Turkey.

[3] As a result, at the time of its formation, it inherited the battle honour awarded to the mounted infantry from Western Australia who served during the Second Boer War.

[4] Under the command of Lieutenant Colonel Arthur Murray Ross, a regular British Army officer,[5] the battalion—as part of the 13th Brigade attached to the 4th Australian Division—sailed for France, arriving in Marseilles on 12 June 1916.

[6][Note 3] The battalion's sole VC recipient was Lieutenant Clifford Sadlier, who received the award for his actions during the attack on Villers-Bretonneux on 24/25 April 1918.

As a result, the battalion was reformed at this time at Subiaco in Western Australia, however, the following year it was moved to Launceston, Tasmania, and then to Sydney, in 1924, where it was attached to the 8th Brigade, which was part of the 1st Division.

[Note 4] Following this, and a return to Australia, the battalion was then deployed to the Solomon Islands, where it saw its heaviest fighting of the war at Tsimba Ridge and Porton Plantation, on Bougainville.

The first two units, the North-West Mobile Force and the Pilbara Regiment, were raised for service in Western Australia and the Northern Territory in 1981–1982.

[4] The current mission of the 51st Battalion, FNQR is that of an RFSU, with the unit tasked with conducting land based and littoral surveillance and reconnaissance in support of national security operations in the inhospitable areas along the northern coast of Australia.