Edward "Teddy" Sheean was an ordinary seaman serving on HMAS Armidale whose death during a Japanese aerial attack on his ship has become a well-known episode in Australian Second World War lore.

Sheean was born at Lower Barrington, Tasmania, on 28 December 1923. He received his education in a Catholic school at Latrobe in Tasmania and, having completed his schooling, worked on farms in the area where he grew up. He enlisted in the Royal Australian Naval Reserve in April 1941 and began his initial training in Tasmania. In February 1942 he was sent to the Flinders Naval Depot at Westernport in Victoria to continue his training, and the following May he was posted to Sydney.

At the end of that month, the vessel on which he was billeted, the former ferry Kuttabul, was sunk during the Japanese midget submarine attack on Sydney Harbour. Fortunately for Sheean he was in Tasmania on home leave that night. He returned to Sydney 11 days later to begin his service as an Oerlikon anti-aircraft gunner on the newly commissioned corvette, HMAS Armidale. Armidale spent her early months on relatively uneventful convoy escort duties along Australia's east and northern coasts.

In October 1942 Armidale's captain, Lieutenant Commander David Richards, was ordered to Darwin and, on 29 November, the corvette began her last operation. Along with two other vessels, she was to undertake a resupply and evacuation mission to Japanese-occupied Timor.

Having been seen by Japanese reconnaissance pilots shortly after leaving the port, Armidale was destined for a dangerous journey. She and the other corvette on the operation, HMAS Castlemaine, missed the rendezvous with the third ship, in Timor's Betano Bay, but met her later some 100 kilometres off-shore. The plan having gone awry, Armidale was ordered to return to Betano the following night. Facing a long day in enemy waters and the certainty of attack, the crew waited.

When in the mid-afternoon she was hit by two aircraft-launched torpedoes, Armidale began to sink fast. Sheean was wounded and, rather than abandon ship, he strapped himself to his Oerlikon and began to engage the attacking aircraft even as the ship sunk beneath him. He shot down two planes, and crewmates recall seeing tracer rising from beneath the surface as Sheean was dragged under the water, firing until the end. He died on 1 December 1942 aged just 18. Only 49 of the 149 men on board survived the attack and subsequent ordeal on rafts and in life boats.

For his courageous action Teddy Sheean was posthumously Mentioned in Despatches; this award was upgraded to the Victoria Cross for Australia in 2020. In 1999 a Collins Class submarine was named after him - the only vessel in the Royal Australian Navy to be named after an ordinary seaman