Cellier's film work includes Morgan! (1966), as Second Counsel; Young Winston (1972), as Captain 35th Sikhs; Luther (1973), as the Prior; Don't Just Lie There, Say Something! (1973), as the Attorney General; Man About the House (1974), as Morris Pluthero; Man Friday (1975), as Carey; Barry Lyndon (1975), as Sir Richard; Sister Dora (1977), as Actor; Jabberwocky (1977), as First merchant; Crossed Swords (1977), as Mean Man; Holocaust 2000 (1977), as Sheckley; The Pumaman (1980), as Martin; Breaking Glass (1980), as Garage Customer; Chariots of Fire (1981), as Head Waiter, as Savoy; And the Ship Sails On (1983), as Sir Reginald J. Dongby; The Last Days of Pompeii (1984), as Calenus; A Room with a View (1985), as Sir Harry Otway, a landlord; Clockwise (1986), as Headmaster; Out of Order (1987), as Home Secretary; Personal Services (1987), as Mr. Marples; Howards End (1992), as Colonel Fussell; Bhaji on the Beach (1993), as Ambrose Waddington; The Remains of the Day (1993), as Sir Leonard Bax; Stanley's Dragon (1994), as Mr. Johnson; Mrs Dalloway (1997), as Lord Lezham; and Ladies in Lavender (2004), as BBC Announcer.