Thomas Welsby Clark was a sailor in the Royal Australian Navy (RAN), whose body was found on a life raft in the Indian Ocean, off Christmas Island, on 6 February 1942. Before his body was identified, he was widely believed to originate from the RAN cruiser HMAS Sydney, which sank off Western Australia in November 1941 after a battle with the German auxiliary cruiser Kormoran. While 318 of 399 Kormoran personnel survived, the crew of Sydney was lost with all 645 hands. He was identified on 19 November 2021 as Able Seaman Thomas Welsby Clark.