Susan Fleetwood (September 21, 1944 – September 29, 1995) was a British actress.
Fleetwood was born in St. Andrews, Scotland, the daughter of Bridget Maureen (née Brereton) and John Joseph Kells Fleetwood. She was a sister of musician Mick Fleetwood. She died in Salisbury, England of ovarian cancer at the age of 51.
After training with RADA, where a student production won her the Bancroft gold medal, in 1964 she joined the company of the Liverpool Everyman theatre, where her fellow student Terry Hands had been appointed director. When Hands moved to the RSC in 1967, she followed. In 1968 at Stratford she gave two commanding performances: in the relatively unpromising part of Cassandra in Troilus and Cressida and as Regan in Lear. In 1969, under the direction of Hands, she movingly doubled the parts Thaisa and Marina in Pericles. In 1974, she played Imogen in John Barton's production of Cymbeline. Many principal roles followed, until in 1977 the former RSC director Peter Hall persuaded her to join him in the National Theatre company where, in addition to playing Ophelia to Albert Finney's Hamlet, she was offered parts from a wider repertory of plays. In the early 1980s she appeared in seasons with both companies; her last season with the RSC was 1990-91.