The squadron became known to the public through its participation in the Great Southern Ocean rescues of wrecked sailors, such as Tony Bullimore and Isabelle Autissier.

In late November, the squadron helped search for survivors from HMAS Sydney following its battle with the German auxiliary cruiser Kormoran, but was unsuccessful.

11 Squadron began flying long-range patrols across the South West Pacific area; these would continue throughout the war and would sometimes be up to 20 hours in duration.

[6] The squadron also flew evacuation missions, repatriating military personnel and civilians back to Australia as the Japanese attacks intensified.

[5] In May, following the Japanese air attacks on Port Moresby, the squadron was withdrawn to Australia, arriving in Bowen, Queensland, from where it flew reconnaissance sorties in support of Allied naval operations during the Battle of the Coral Sea.

The squadron's most notable achievement in this role was the mining of Manila harbour in December 1944,[8] which required three aircraft to fly over 14,500 kilometres (9,000 mi) in the RAAF's longest mission of the war.

After Japan surrendered in August 1945, its focus shifted to humanitarian efforts, air dropping supplies to Allied personnel in prisoner-of-war camps, and repatriating newly liberated POWs back to Australia.

11 Squadron was re-formed at RAAF Base Rathmines, New South Wales, drawing personnel and aircraft from the former Search and Rescue Wing.

In September that year, the squadron lost one aircraft in a crash on Lord Howe Island during a night navigation exercise, resulting in the deaths of seven of the nine crewmembers.

[5] In 1959, the squadron's Neptunes were flown to the United States and upgraded with jet engines; one aircraft was lost in a crash near Richmond early that year, resulting in the deaths of the entire crew.

[4] In this role, the squadron has taken part in several high-profile rescues of wrecked sailors in the Great Southern Ocean, including those of Tony Bullimore and Isabelle Autissier.

11 Squadron Poseidon was deployed to Japan to conduct maritime surveillance to prevent sanctions evasions by North Korea as part of Operation Argos.

[21] In October 2019, a Poseidon was deployed to the Middle East in support of a US-led International Maritime Security Construct, which includes forces from the US, Saudi Arabia, Bahrain and the UK.

[24] On 26 May 2022, during a Defence Force maritime surveillance mission, a Poseidon later identified as A47-008, callsign ASY-189, was intercepted by a PLAAF J-16 fighter jet in International Airspace over the South China Sea.