| Actor Name | Character Name |
| Robert Duvall Donald Pleasence Don Pedro Colley Maggie McOmie Ian Wolfe Marshall Efron Sid Haig John Pearce Irene Forrest Gary Alan Marsh John Seaton Eugene I. Stillman Raymond Walsh Mark Lawhead Robert Feero Johnny Weissmuller Jr Claudette Bessing Susan Baldwin James Wheaton Henry Jacobs William Love Doc Scortt Gary Austin Scott L. Menges Toby L. Stearns Paul K. Haje Ralph Chesse Mello Alexandria Barbara J. Artis Morris D. Erby Willie C. Barnes Richard Quinnell Jean M. Durand Scott Beach Neva Beach Terence McGovern Julie Payne James Cranna Ruth Silveira Bruce Mackey David Ogden Stiers Bart Patton John Rigg |
THX 1138 SEN 5241 SRT, the hologram LUH 3417 PTO TWA NCH DWY IMM CAM, the radical OUE JOT TRG Shell Dweller in Prison Chrome Robot Chrome Robot ELC Police Control Officer Voice of OMM Mark 8 Student Mark 8 Instructor Monk Man in Yellow Child Child Trial Prosecutor Trial Proctor Hologram Dancer Hologram Dancer Hologram Newscaster Hologram Comedian Hologram Straight-Man Listener Announcer Announcer Announcer Announcer Announcer Announcer Announcer Announcer Announcer Computer Operator (uncredited) |
