RFA Olwen (A122) was an Ol-class "fast fleet tanker" of the Royal Fleet Auxiliary. The lead ship of her class, and launched in 1964 as RFA Olynthus, the second ship to bear this name, she was renamed Olwen in 1967 to avoid confusion with HMS Olympus. She was decommissioned in 1999 and laid up at Portsmouth, before being broken up at Alang, India in 2001.