| Movie | 1984 | The Killing Fields | Sydney Schanberg | |
| Movie | 1980 | Heaven's Gate | Frank Canton | |
| Movie | 1974 | The Great Gatsby | Nick Carraway | |
| Movie | 1986 | Hannah and Her Sisters | David (uncredited) | |
| Movie | 1989 | Crimes and Misdemeanors | Ben | |
| Movie | 1994 | Serial Mom | Eugene Sutphin | |
| Movie | 1987 | September | Peter | |
| Movie | 1977 | Capricorn One | Lt. Col. Peter Willis | |
| Movie | 1980 | Hopscotch | Jack Cutter | |
| Movie | 2003 | Le Divorce | Chester Walker | |
| Movie | 1985 | Warning Sign | Cal Morse | |
| Movie | 1975 | Rancho Deluxe | Cecil Colson | |
| Movie | 1978 | Interiors | Mike | |
| Movie | 1995 | The Journey of August King | Mooney Wright | |
| Movie | 2002 | The Matthew Shepard Story | Dennis Shepard | |
| Movie | 1997 | Shadow Conspiracy | The President | |
| Movie | 1991 | The Man in the Moon | Matthew Trant | |
| Movie | 1991 | Mindwalk | Jack Edwards | |
| Movie | 2010 | The Rally to Restore Sanity and/or Fear | Self | |
| Movie | 1989 | Welcome Home | Woody | |
| Movie | 1973 | The Glass Menagerie | Tom Wingfield | |
| Movie | 1969 | Generation | Desmond | |
| Movie | 1994 | The Enemy Within | President William Foster | |
| Movie | 1974 | Reflections of Murder | Michael Elliott | |
| Movie | 1996 | The Proprietor | Harry Bancroft | |
| Movie | 2024 | Merchant Ivory | Self | |
| Movie | 1979 | Eagle's Wing | White Bull | |
| Movie | 1986 | The Fifth Missile | Capt. Allard Renslow | |
| Movie | 1987 | Swimming to Cambodia | Additional cast from 'The Killing Fields' (archive footage) | |
| Movie | 1982 | Games Mother Never Taught You | David Bentells | |
| Movie | 1975 | Journey into Fear | Mr. Graham | |
| Movie | 1987 | The Room Upstairs | Travis Coles | |
| Movie | 1998 | Miracle at Midnight | Dr. Karl Koster | |
| Movie | 1969 | Three | Taylor | |
| Movie | 1988 | Terrorist on Trial: The United States vs. Salim Ajami | Jim Delmore | |
| Movie | 1995 | Nixon | Richard Helms | |
| Movie | 1989 | Lantern Hill | Andrew Stuart | |
| Movie | 1972 | Mahoney's Last Stand | Felix | |
| Movie | 2024 | A Case for Love | Self | |
| Movie | 1994 | David's Mother | John Nils | |
| Movie | 1993 | I'll Fly Away: Then and Now | Forrest Bedford | |
| Movie | 1983 | Dempsey | Doc Kearns | |
| Movie | 1980 | Sweet William | William McClusky | |
| Movie | 1994 | Assault at West Point: The Court-Martial of Johnson Whittaker | Daniel Chamberlain | |
| Movie | 1970 | Cover Me Babe | Cameraman | |
| Movie | 1990 | Night of 100 Stars III | Self | |
| Movie | 1971 | Who Killed Mary Whats'ername? | Alex Monte | |
| Movie | 2015 | Please Be Normal | Dad | |
| Movie | 2016 | Anesthesia | Prof. Walter Zarrow | |
| Movie | 1984 | The Boy Who Loved Trolls | Ofoeti | |
| Movie | 1986 | Flagrant désir | Inspecteur Gerry Morrison | |
| Movie | 1985 | Love Lives On | Bernie | |
| Movie | 1998 | Exiled | Jack McCoy | |
| Movie | 2024 | The Six Triple Eight | Franklin Delano Roosevelt | |
| Movie | 1986 | Just Between Friends | Harry Crandall | |
| Movie | 1993 | A Captive in the Land | Royce | |
| Movie | 1973 | Much Ado About Nothing | Benedick | |
| Movie | 1972 | Savages | James, the Limping Man | |
| Movie | 2000 | A House Divided | David Dickson | |
| Movie | 2016 | Miss Sloane | George Dupont | |
| Movie | 1995 | Amazing Stories: The Movie IV | (archive footage) | |
| Movie | 1967 | Fitzwilly | Oliver | |
| Movie | 1987 | Devil's Paradise | Jones | |
| Movie | 1966 | The Plastic Dome of Norma Jean | Andy | |
| Movie | 1976 | Sweet Revenge | Le Clerq | |
| Movie | 1985 | Finnegan Begin Again | Paul Broadbent | |
| Movie | 1983 | In Defense of Kids | Paul Wilcox | |
| Movie | 2017 | Monkey Business: The Adventures of Curious George's Creators | Narrator (voice) | |
| Movie | 2018 | On the Basis of Sex | Erwin Griswold | |
| Movie | 2020 | The Man in the Woods | Headmaster Waldorf | |
| Movie | 1994 | Tennessee Williams: Orpheus of the American Stage | Tom Wingfield (archive footage) | |
| Movie | 2018 | The Mayo Clinic | Charlie Mayo (voice) | |
| Movie | 2006 | The Best of The Tony Awards: The Plays | John Honeyman (segment "A Walk in the Woods") | |
| Movie | 1988 | A Walk in the Woods | John Honeyman | |
| Movie | 1999 | In Bad Taste | Self | |
| Movie | 2018 | Jane Fonda in Five Acts | Self - Actor | |
| Movie | 2015 | Dean Smith | Narrator | |
| Movie | 2017 | Dateline: Saigon | Narrator (voice) | |
| Movie | 1992 | Earth and the American Dream | Reader (voice) | |
| Movie | 1980 | Friendly Fire | C.D.B. Bryan | |
| Movie | 2021 | Kurt Vonnegut: Unstuck in Time | Self (voice) | |
| Movie | 1999 | Moment of Impact: Stories of the Pulitzer Prize Photographs | Self / Host / Narrator | |
| Movie | 2020 | Gatsby in Connecticut: The Untold Story | Self | |
| Movie | 2003 | The Commission | J. Lee Rankin | |
| Movie | 1999 | The Unfinished Journey | Narrator (voice) | |
| Movie | 2015 | And It Was Good | Judge Alexander Baas / Doctor / Gravedigger | |
| Movie | N/A | Rain Falls from Earth: Surviving Cambodia's Darkest Hour | Self (voice) | |
| Movie | 2004 | Hammer and Cycle | Self - Narrator | |
| TV Show | 1990 | Law & Order | Jack McCoy | 405 |
| TV Show | 1982 | Q.E.D. | | 7 |
| TV Show | 1989 | Tales from the Crypt | G.G. Devoe (segment "As Ye Sow") | 1 |
| TV Show | 1984 | Jeopardy! | | 1 |
| TV Show | 2007 | Masters of Science Fiction | | 1 |
| TV Show | 2005 | The Colbert Report | | 1 |
| TV Show | 1991 | I'll Fly Away | Forrest Bedford | 39 |
| TV Show | 1993 | Homicide: Life on the Street | Jack McCoy | 2 |
| TV Show | 1951 | Hallmark Hall of Fame | Travis Coles | 1 |
| TV Show | 1980 | Oppenheimer | Robert Oppenheimer | 7 |
| TV Show | 1990 | The Civil War | Abraham Lincoln | 9 |
| TV Show | 1997 | The View | Self | 1 |
| TV Show | 2012 | The Newsroom | Charlie Skinner | 25 |
| TV Show | 1961 | Dr. Kildare | Mark | 2 |
| TV Show | 1997 | Thomas Jefferson | Thomas Jefferson (voice) | 2 |
| TV Show | 2015 | Grace and Frankie | Sol Bergstein | 94 |
| TV Show | 1999 | Family Guy | Bruce Kaplan (voice) | 2 |
| TV Show | 1985 | Amazing Stories | Jordan Manmouth | 1 |
| TV Show | 2023 | Liv Ullmann: A Road Less Travelled | Self | 3 |
| TV Show | 1988 | Lincoln | Abraham Lincoln | 2 |
| TV Show | 1995 | Time Life's Lost Civilizations | Narrator | 10 |
| TV Show | 2013 | Jo | | 1 |
| TV Show | 2015 | The Late Show with Stephen Colbert | Self | 2 |
| TV Show | 1997 | Lewis & Clark - The Journey of the Corps of Discovery | Thomas Jefferson (voice) | 2 |
| TV Show | 1989 | The Nightmare Years | Bill Shirer | 4 |
| TV Show | 1999 | Law & Order: Special Victims Unit | Jack McCoy | 4 |
| TV Show | 2005 | Law & Order: Trial by Jury | Jack McCoy | 2 |
| TV Show | 2017 | Godless | Marshall John Cook | 7 |
| TV Show | 1975 | People's Choice Awards | Self - Presenter | 1 |
| TV Show | 2022 | The Dropout | George Shultz | 5 |
| TV Show | 1997 | The View | Self - Guest | 1 |
| TV Show | 1975 | Saturday Night Live | Self - Cameo (uncredited) | 3 |
| TV Show | 2011 | Prohibition | Reader (voice) | 3 |
| TV Show | 1992 | HBO First Look | | 1 |
