HMAS Diamantina named after the Diamantina River in Queensland, is a that served the Royal Australian Navy (RAN). Constructed in the mid-1940s, Diamantina was active from 1945 until 1946, was placed in reserve, then was recommissioned as a survey ship from 1959 until 1980.
Following her second decommissioning, the frigate was preserved at the Queensland Maritime Museum as a museum ship. She was the last World War II-era frigate to leave RAN service, and of the 151 River-class frigates constructed for 19 navies worldwide, Diamantina is the only one preserved as a museum ship.