Poseidon was an Australian Thoroughbred Hall of Fame racehorse. He won 19 races over distances ranging from five furlongs to three miles. Sixteen of these wins were "Principal Races", eight of them now of Group 1 (G1) status.

The Australian Racing Hall of Fame is part of the Australian Racing Museum which documents and honours the horseracing legends of Australia. The museum officially opened in 1981 and created the Hall of Fame in 2000.