Ellen BurstynChris MacNeil Jason MillerFather Damien Karras Max von SydowFather Lankester Merrin Lee J. CobbLt. Bill Kinderman William O'MalleyFather Joseph Kevin Dyer Peter MastersonDr. Barringer Jack MacGowranBurke Dennings Arthur StorchPsychiatrist Vasiliki MaliarosMary Karras John MahonLanguage Lab Director Wallace RooneyBishop Michael Ron FaberChuck / Demon (voice) Donna MitchellMary Jo Perrin Robert GerringerSenator at Party Mercedes McCambridgeDemon (voice) Paul BatesonRadiologist's Assistant (uncredited) Elinore BlairNurse (uncredited) William Peter BlattyThe Producer (uncredited) / Novel / Producer Mary BoylanFirst Mental Patient (uncredited) Dick CallinanAstronaut (uncredited) Mason CurryDoctor (voice) (uncredited) Toni DarnayViolent psychotic patient (uncredited) Eileen DietzDemon / Regan Double (uncredited) Joanne DusseauSenator's Wife (uncredited) Bernard EismannMinor Role (uncredited) Beatrice HunterMinor Role (uncredited) Yvonne JonesBellevue Nurse (uncredited) Don LaBonteMinor Role (uncredited) Barton LaneAngiography Doctor (uncredited) Ann MilesSpiderwalk (uncredited) John NicolaPriest (uncredited) Vincent RussellSubway Vagrant (uncredited) Gerard F. YatesPriest Singing Around Piano at Party (uncredited) Rita Sakellariou(her voice on the radio) William FriedkinRegisseur William Peter BlattyThe Producer (uncredited) / Novel / Producer Noel MarshallExecutive Producer David SalvenAssociate Producer Bill MalleyProduction Design Jerry WunderlichSet Decoration Owen RoizmanDirector Of Photography Joe FretwellCostume Design William A. FarleyHairstylist Terence A. DonnellyFirst Assistant Director Nicholas SgarroScript Supervisor Ross TaylorSound Effects Editor Jack NitzscheOriginal Music Composer Fred J. BrownSound Effects Editor 
