HMAS Cairns

HMAS Cairns is a Royal Australian Navy base at Cairns, Queensland, on the shore of Trinity Bay adjacent to Trinity Inlet. It is owned by the Department of Defence and operated by the RAN as a minor war vessel base, and is responsible for Australian naval activity off the north-east coast, an area extending from Rockhampton to Thursday Island.

The base is the parent establishment for patrol and hydrographic vessels in northern Queensland. Its garrison comprises elements of the Australian Patrol Boat Group and the Royal Australian Navy Hydrographic Service. Cairns homeports Cape class and Armidale class patrol boats and berths the RAN's hydrographic fleet, including the Leeuwin class survey vessels.

Facilities include maintenance and support infrastructure for minor war vessels. The base and adjacent commercial industry facilities have been designated Regional Maintenance Centre North East, the first of four dedicated naval support centres established at selected ports, providing sustainment for vessels operating in the region.

The RAN used Cairns as a port of call from before the Second World War, but no permanent presence existed until 1971, when maintenance and support facilities for patrol boats were established. The establishment was commissioned as HMAS Cairns in 1974 as the parent unit for the patrol vessels and hydrographic ships based there. From 2016 the base was progressively redeveloped, with an A$120 million programme over ten years and an associated increase in personnel numbers, and further upgrades were announced in 2021 to support Arafura class offshore patrol vessels.