Gillian Bailey or Gilli Bush-Bailey (born 14 June 1955 in Wimbledon, London) is a British academic and former actress.
She was mainly known as a child actress. Her best-known role was as Billie in Here Come the Double Deckers (1970–71). Other roles included Phyllis in a television version of The Railway Children (1968), Janey in The Witch's Daughter (1971), and Callie in Follyfoot (1971–73).
She was less prominent as an adult, although she remained working being cast in roles such as Jinny Carter in series 1 of Poldark (1975), Ravella in the first episode of Blake's 7 (1978), and Maureen Galbraith in the BBC TV series County Hall (1982). In the 1990s she found that work dried up and began working as a script reader. In 1992 she returned to complete her education at Kingston University. After a period at the Drama and Theatre department at the Royal Holloway, University of London she is now Professor of Women's Performance Histories at the Royal Central School of Speech and Drama in London.
She married Richard Everett in 1974, and the couple had a daughter, Rebecca.