At the outbreak of the Second World War 11 Squadron moved to Port Moresby, having been formed as a general reconnaissance squadron at Richmond in New South Wales on 21 September 1939. The squadron's small flight of Seagull and Empire flying boats immediately began patrolling the Thursday Island, Tulagi, New Zealand, and Bougainville. In 1941 the unit began flying Catalina aircraft, with one detached to join the search for HMAS Sydney and any survivors.

Squadron aircraft continued to carry out bombing attacks against Japanese shipping at Rabaul and other targets on Japanese-occupied islands. With Japanese naval and air attacks on Port Moresby escalating, the squadron withdrew to Bowen in Queensland on 7 May 1942. During the move unit aircraft flew reconnaissance missions for naval vessels engaged in the Battle of the Coral Sea. Towards the end of 1942 the unit relocated to Cairns and commenced night raids against enemy shipping and submarines attempting to land supplies around Lae, Salamaua, and Finschafen. Unit Catalinas mined enemy harbours and dropped supplies to coastwatchers in the Solomons, New Britain, and New Ireland between April and July 1943.

Between September and December 1943 combined attacks were made against Lakunai, Vunkanau, and Rapopo airfields on Rabaul, and on enemy targets at Ambon, Kavieng, and Gasmatta. Much of 1944 was taken up with mine-laying operations and also with anti-submarine patrols, shipping searches, and seaward reconnaissance. One of the units most successful missions was the mining of Manila Harbour on 14 December, prior to the invasion of Mindora Island by Allied forces.

At the end of the war, 11 Squadron dropped food and medical supplies to prisoner-of-war camps across south-east Asia and flew survivors back to Australia. Aircraft were withdrawn early the following year and the squadron was disbanded on 15 February 1946.
References
  • Minty, Albert Ernest 'Bill', Black Cats: the real story of Australian long range Catalina strike force in the Pacific War, Solomons to Singapore, Cairns to the coast of China(Point Cook: RAAF Museum, 1994)
  • Royal Australian Air Force Historical Section, Units of the Royal Australian Air Force : a concise history: volume 4 Maritime and transport units(Canberra : AGPS Press, 1995)
  • Barnes, Norman, The RAAF and the flying squadrons(St Leonards, N.S.W : Allen & Unwin, 2000)
  • Honan, Robert Frederick, That's that : memoirs of wartime service 1939-1945(Trinity Gardens, S. Aust.: R.F. Honan, 1989)
  • Riddell, Jack, Catalina squadrons, first and furthest : recounting the operations of RAAF Catalinas, May 1941 to March 1943(Murwillumbah, N.S.W.: J. Riddell, 1992)
    • CategoryUnit
      Related conflicts Second World War, 1939-1945
      Battle honours
    • Coral Sea
    • Darwin 1941-1944
    • Dutch New Guinea
    • Moresby 1942-1943
    • New Britain 1943
    • New Guinea 1942-1944
    • New Guinea 1943-1944
    • Pacific 1941-1945
    • Philippines 1944
    • Rabaul 1942
      • Commanding officers
      • Alexander, James
      • Atkinson, Richard Ashley
      • Bolitho, William Keith
      • Chapman, F S
      • Cohen, Julius Allan
      • Coventry, Geoffrey William
      • Green, Redmond Forrest Michael
      • Lawrence, Denis Russell
      • Middlemiss, Stewart Carlyle
      • Pearce, Charles William
        • Decorations2 DSO; 13 DFC; 3 AFC; 13 DFM; 1 BEM; 8 MID
          Alternative names
          • 11 Sqn
          • 11 Sqn RAAF
          • 11 Squadron
          • 11 Squadron RAAF
          • No. 11 Squadron
          Unit hierarchy