Rosie Marcel (born 6 May 1977 in Roehampton, London) is an English actress. She is best known as Jac Naylor, the consultant cardiothoracic surgeon in the BBC drama series, Holby City. She is the daughter of television director Terry Marcel and sister of writer and actress Kelly Marcel.
Marcel describes herself as being from a 'dramatic' family, and she had her first job at the age of three as a fairy in A Midsummer Nights Dream at the National Theatre. In November 2005, Marcel joined Holby as Jac Naylor. Prior to this she appeared in over twenty productions of The Bill, in which her character had an affair with Sergeant Dale Smith.
Marcel's mother, Lindsey Brook was an actress and her father, Terry Marcel, is a director; they divorced in 1995. Her older sister Kelly is a writer and actress who has appeared in both Holby City and The Bill, but is now best known as the writer and executive producer of the television series Terra Nova They also have a younger brother, Luke.