뮤지컬배우, TV, 영화 배우. 1965년 브로드웨이 뮤지컬 <Man of La Mancha>에서 돈키호테로 잘 알려진 배우이다. 그가 부른 “The Impossible Dream”은 전 세계적으로도 잘 알려졌다. 1953년 <Kismet>에도 출연하였다.

일리노이즈주 시카고 출생. 카멜 고등학교를 졸업하였고, 로욜라 대학을 졸업하였다. 시카고에서 뉴욕으로 이사하여 배우 생활을 시작한다.

킬리가 브로드웨이에 처음 데뷔한 작품은 연극 <Misalliance>이었고, 같은 해 12월에 뮤지컬 <Kismet>에 출연하였다. <No Strings>, <I Had a Ball>, <Redhead>, <The Incomparable Max> 등에 출연하였다. <Man of La Mancha>에서 세르반테스와 돈키호테 역으로 출연하여 남우주연상을 수상하였다.

킬리는 영화, TV 등에 출연하였는데 <The Thorm Birds, 1983>, <A Year in the Life, 1986, 1987-1988> 등에 출연하였고, 에미 어워즈와 골든 글로브 어워즈에서 남우주연상을 수상하였다.
<Jurassic Park> 등에 출연하였다. 1999년 뉴욕에서 골수암으로 숨을 거두었다.

Film <Nice Shot, 2001> Actor(Don)
<Blue Moon, 1999> Actor(Jimmy Keating)
<Patch Adams, 1998> Actor(Dr. Titan)
<Ally McBeal, 1998> Actor(Seymore Little)
<Time to Say Goodbye?, 1997> Actor(Dr. Gerald Klooster)
<Mary & Tim, 1996> Actor(Ron Melville)
<The Rockford Files: Punishment and Crime, 1996> Actor(Frank Dougherty)
<Phenomenon, 1996> Actor(Dr. Wellin)
<The Great Defender, 1995> Actor(Jason DeWitt)
<Secrets, 1995> Actor(Dr. Will Berter)
<Christy, 1994> Actor(Dr. Ferrand)
<A Passion for Justice: The Hazel Brannon Smith Story, 1994> Actor(Earl Clayburn)
<Picket Fences, 1992-1994> Actor(Hayden Langston)
<The Cosby Mysteries, 1994> Actor(Sears Cushing)
<Star Trek: Deep Space Nine, 1993> Actor(Dr. Gideon Seyetik)
<The Visual Bible: Matthew, 1993> Actor(Old Matthew)
<Jurassic Park, 1993> Voice
<Tribeca, 1993> Actor(Winston Hannah)
<Mastergate, 1992> Actor(Archer Bowman)
<The Ray Bradbury Theater, 1992> Actor(Doug)
<Absolute Strangers, 1991> Actor(Doctor R.J. Cannon)
<Separate But Equal, 1991> Actor(Earl Warren)
<Gunsmoke: The Last Apache, 1990> Actor(Chalk Brighton)
<Aladdin, 1990> Actor(Magician)
<The Final Days, 1989> Actor(J. Fred Buzhardt)
<Miami Cops, 1989> Actor
<My First Love, 1988> Actor(Sam Morrissey)
<A Year in the Life, 1987-1988> Actor(Joe Gardner)
<The Twilight Zone, 1986> Actor(Lancelot, segment The Last Defender of Camelot)
<If Tomorrow Comes, 1986> Actor(Gunther Hartog)
<A Year in the Life, 1986> Actor(Joe Gardner)
<Do You Remember Love, 1985> Actor(George Hollis)
<A.D., 1985> Actor(Claudius)
<The Bad Seed, 1985> Actor(Richard Bravo)
<Hotel, 1985> Actor(Matt Carmichael)
<The Canterville Ghost, 1985> Actor(Sir Simon de Canterville)
<Adventures of Huckleberry Finn, 1985> Actor(Colonel Grangerford)
<George Washington, 1984> Actor(George Mason)
<Parade of Stars, 1983> Actor(Don Quixote/Cervantes)
<The Thorn Birds, 1983> Actor(Paddy Cleary)
<Isabel's Choice, 1981> Actor(Lyman Jones)
<Golden Gate, 1981> Actor(Thomas J. Kingsley)
<Endless Love, 1981> Actor(Arthur Axelrod)
<Angel on My Shoulder, 1980> Actor(Nick)
<Jesus, 1979> Voice(Narrator/St. Luke)
<Looking for Mr. Goodbar, 1977> Actor(Mr. Dunn)
<The Andros Targets, 1977>
<How the West Was Won, 1977> Actor(Timothy Macahan)
<Hawaii Five-O, 1976> Actor(Sam Patton)
<The Macahans, 1976> Actor(Timothy Machan)
<Medical Story, 1975> Actor(Mark Kellerman)
<Friendly Persuasion, 1975> Actor(Jess Birdwell)
<The Little Prince, 1974> Actor(The Pilot)
<Cannon, 1974> Actor(Bishop Michael Harrigan)
<Columbo, 1974> Actor(Mark Halperin)
<Give Me Liberty, 1974> Actor
<Jigsaw, 1972> Actor(District Attorney Dan Bellington)
<The F.B.I., 1968-1972> Actor(John Streyer)
<Night Gallery, 1969-1972> Actor(Joseph Strobe)
<All the Way Home, 1971> Actor(Jay Follet)
<Hallmark Hall of Fame, 1971> Actor(Jay Follet)
<Murder Once Removed, 1971> Actor(Frank Manning)
<The Name of the Game, 1970-1971> Actor(Arlen McKittrick)
<Medical Center, 1971> Actor(Dr. Thomas Patton)
<Incident in San Francisco, 1971> Actor(Robert Harmon)
<The Ceremony of Innocence, 1970> Actor(King Ethelred)
<Bonanza, 1970> Actor(Sheriff Gideon Yates)
<The New People, 1969> Actor(Hannichek)
<Judd for the Defense, 1969> Actor(Barnaby Cutler)
<Pendulum, 1969> Actor(Woodrow Wilson King)
<Garrison's Gorillas, 1968> Actor(Field Marshal Donner)
<The Danny Thomas Hour, 1968>
<Coronet Blue, 1967> Actor(Dr. Courtland)
<The Long, Hot Summer, 1965> Actor(Senator Jonathan Dane)
<Slattery's People, 1964> Actor(Dr. Robert Kelly)
<Kraft Suspense Theatre, 1964> Actor(Lou Franklin)
<The Defenders, 1961-1964> Actor(Acting Governor White)
<The Nurses, 1964> Actor(Manning)
<Ben Casey, 1964> Actor(Dr. Paul Hamilton)
<The Great Adventure, 1964> Actor(Colonel Edwin L. Drake)
<The Eleventh Hour, 1963> Actor(Kenneth Newell)
<The Alfred Hitchcock Hour, 1963> Actor(Jim Derry)
<Alcoa Premiere, 1962> Actor(Dr. Jonathan Bent)
<Cain's Hundred, 1962> Actor(Doug Crawford)
<The Edge of Night, 1956, 1961> Actor(Leland Davis Breckenridge)
<Dr. Kildare, 1961> Actor(Fred Carroll)
<The United States Steel Hour, 1953-1961> Actor(Charlie Webb)
<Play of the Week, 1961> Actor
<Goodyear Theatre, 1958> Actor(Captain Josiah Newman)
<Alfred Hitchcock Presents, 1958> Actor(Harry Adams)
<Decision, 1958> Actor
<Kraft Television Theatre, 1951-1958> Actor(Fred Staples)
<Playhouse 90, 1957-1958> Actor(Bob Lyttleton)
<The Power of the Resurrection, 1958> Actor(Peter)
<Spanish Affair, 1957> Actor(Merritt Blake)
<Studio One, 1951-1957> Actor(Calvin)
<Homeward Borne, 1957>
<The Alcoa Hour, 1957> Actor(Peter Melnecke)
<The Kaiser Aluminum Hour, 1957> Actor(David Oro)
<Armstrong Circle Theatre, 1955>
<The Phenix City Story, 1955> Actor(John Patterson)
<Climax!, 1955> Actor(Charley Kincaid)
<General Electric Theater, 1955>
<Blackboard Jungle, 1955> Actor(Joshua Y. Edwards)
<Justice, 1954>
<Medallion Theatre, 1954>
<The Web, 1950-1953>
<Danger, 1951-1953>
<The Revlon Mirror Theater, 1953>
<Pickup on South Street, 1953> Actor(Joey)
<Short Short Dramas, 1952-1953>
<Tales of Tomorrow, 1953>
<Eight Iron Men, 1952> Actor(Pvt. Coke)
<Suspense, 1950-1952> Actor(Webb Wilson)
<Curtain Call, 1952>
<Celanese Theatre, 1952>
<The Sniper, 1952> Actor(Dr. James G. Kent)
<Lux Video Theatre, 1952> Actor(Dan)
<The Mob, 1951> Actor(Thomas 'Tom' Clancy)
<Pulitzer Prize Playhouse, 1951>
<The Clock, 1950-1951>
<Robert Montgomery Presents, 1950>