Julia Kathleen Nancy McKenzie is an English actress, singer, presenter, and theatre director. She has premièred leading roles written by both Alan Ayckbourn and Stephen Sondheim. On television, she is known for her BAFTA Award nominated role as Hester Fields in the sitcom Fresh Fields (1984–1986) and its sequel French Fields (1989–1991), and as Miss Marple in Agatha Christie's Marple (2009–2013).

Miss Jane Marple is a fictional character in Agatha Christie's crime novels and short stories. Miss Marple lives in the village of St. Mary Mead and acts as an amateur consulting detective. Often characterized as an elderly spinster, she is one of Christie's best-known characters and has been portrayed numerous times on screen. Her first appearance was in a short story published in The Royal Magazine in December 1927, "The Tuesday Night Club", which later became the first chapter of The Thirteen Problems (1932). Her first appearance in a full-length novel was in The Murder at the Vicarage in 1930, and her last appearance was in Sleeping Murder in 1976.