| Film |
| Year | Film | Role | Notes |
| 1962 | War Hunt | Sgt. Stan Showalter | |
| 1964 | One Man's Way | Leonard Peal (Grown) | |
| 1965 | Those Calloways | Whit Turner | |
| 1970 | MASH | Capt. Augustus Bedford 'Duke' Forrest | |
| 1971 | Wild Rovers | John Buckman | |
| Harold and Maude | Motorcycle Officer | |
| 1972 | Fuzz | Det. Bert Kling | |
| 1974 | Thieves Like Us | Dee Mobley | |
| Arrivano Joe e Margherito | Margherito | |
| Big Bad Mama | Fred Diller | |
| 1975 | The Devil's Rain | Tom Preston | |
| 1976 | ...e tanta paura | Chief Inspector | |
| Madama, La | Rick Dylan | |
| 1977 | The Turning Point | Wayne | |
| 1978 | Up in Smoke | Strawberry | |
| Ice Castles | Marcus Winston | |
| 1979 | Alien | Dallas | |
| 1981 | A Dangerous Summer | Howard Anderson | |
| Savage Harvest | Casey | |
| Silence of the North | Walter Reamer | |
| 1982 | Fighting Back | John D'Angelo | |
| 1983 | The Dead Zone | Sheriff George Bannerman | |
| 1986 | Top Gun | Cmdr. Mike 'Viper' Metcalf | |
| SpaceCamp | Zach Bergstrom | |
| Opposing Force | Logan | |
| Wisdom | Lloyd Wisdom | |
| 1987 | Maid to Order | Charles Montgomery | |
| The Big Town | Phil Carpenter | |
| 1988 | Honor Bound | Sam Cahill | |
| Poltergeist III | Bruce Gardner | |
| 1989 | Big Man on Campus | Dr. Webster | |
| Steel Magnolias | Drum Eatenton | |
| 1990 | The Rookie | Eugene Ackerman | Child In The Night (1990) with Jobeth Williams also From The Poltergeist Saga |
| 1992 | Poison Ivy | Darryl Cooper | |
| Knight Moves | Capt. Frank Sedman | |
| Wild Orchid 2: Two Shades of Blue | Ham McDonald | Direct-to-Video Release |
| A River Runs Through It | Reverend Maclean | |
| Singles | Mayor Weber | |
| 1997 | Contact | David Drumlin | |
| 1998 | Smoke Signals | Police Chief | |
| 1999 | The Other Sister | Dr. Radley Tate | |
| 2001 | Texas Rangers | Richard Dukes | |
| 2002 | Tuscaloosa | | |
| Changing Hearts | Johnny Pinkley | |
| Greenmail | Tom Bradshaw | Direct-to-Video Release |
| 2003 | Tears of the Sun | Captain Bill Rhodes | |
| Swing | George Verdi | |
| 2006 | Bonneville | Emmett | |
| 2007 | The Velveteen Rabbit | Horse | |
| 2008 | Beer for My Horses | Sheriff Wilson Landry | |
| 2009 | Whiteout | Dr. John Fury | |
| For Sale by Owner | Clive Farrier | post-production |
| Rivers of a Lost Coast | Narrator | |
| Television |
| Year | Title | Role | Notes |
| 1962-1967 | Combat! | Soldier (uncredited)
Glinski (uncredited)
Hicks
Burke
Sgt. Decker | Episode: Combat Front
Episode: A Day in June
Episode: The Prisoner
Episode: Losers Cry Deal
Episode: Nothing to Lose
Episode: The Gantlet |
| 1962-1971 | The Virginian | Eric Kroeger
Rev. Paul Martin
Billy Landers
Moran
Rafe
Bobby Allen | Episode: Impasse
Episode: The Secret of Brynmar Hall
Episode: The Showdown
Episode: The Crooked Path
Episode: The Saddle Warmer
Episode: Nan Allen |
| 1963 | Laramie | | Episode: No Place to Run |
| The Real McCoys | Mailman | Episode: Aunt Win Steps In |
| The Alfred Hitchcock Hour | Dr. Frank Farmer | Episode: Run for Doom |
| My Three Sons | Young Steve | Episode: The Proposals |
| 1963-1968 | Death Valley Days | Emmett Dalton
Patrick Hogan
Sam Clemens
| Episode: Three Minutes to Eternity
Episode: Honor the Name Dennis Driscoll
Episode: The Book
Episode: Sense of Justice
Episode: Ten Day Millionaires |
| 1964 | Wagon Train | Hamish Browne | Episode: The Last Circle Up |
| My Favorite Martian | Dr. Edgar Edgarton | Episode: Miss Jekyll and Hyde |
| 1964-1967 | Twelve O'Clock High | Lt. Ryan
Lt. Parmalee
Sgt. Ben Rodale
Lt. Paddy Gialella
Tech. Sgt. Neely | Episode: Spiders Sometimes Kill
Episode: Those Who Are About to Die
Episode: The Came the Mighty Hunter
Episode: Twenty Fifth Mission
Episode: Long Time Dead |
| 1964, 1973 | Bonanza | Jerry
Corporal Bill Tanner | Episode: Thanks for Everything, Friend
Episode: The Hunter |
| 1965 | Voyage to the Bottom of the Sea | Frank Richardson | Episode: The Enemies |
| Disney's Wonderful World | Corky Mardis | Episode: ...The Daily Press vs. City Hall |
| 1965, 1966 | The Fugitive | Neely Hollister
Pete | Episode: Nicest Fella You'd Ever Want to Meet
Episode: Joshua's Kingdom |
| 1965-1972 | Gunsmoke | Edmund Dano
Ben Stone
Orv Timpson
Fred Garth
Tuck Frye | Episode: The Pretender
Episode: The Jailer
Episode: The Moonstone
Episode: The Noose
Episode: Jubilee |
| 1966 | The Time Tunnel | Matthew Gebhardt | Episode: The Death Trap |
| 1966-1972 | The F.B.I. | Robert Hastings
John Clarence Rim
Thorn Hazard
Bill Leonard | Episode: The Assassin
Episode: The Legend of John Rim
Episode: Unknown Victim
Episode: The Deadly Species |
| 1967 | Mannix | Morgan Carpenter | Episode: Warning - Live Blueberries |
| Hallmark Hall of Fame | Trapani | Episode: A Bell for Adano |
| 1968 | Cimarron Strip | Enoch Shelton | Episode: Knife in the Darkness |
| Run for Your Life | Lou Patterson | Episode: The Killing Scene |
| Felony Squad | Gerald Gardner | Episode: Matched for Murder |
| 1969 | The Outsider | Arnie Cambor | Episode: A Bowl of Cherries |
| Lancer | Bill Blake | Episode: The Knot |
| 1970 | Hawaii Five-O | Lew Morgan | Episode: Most Likely to Murder |
| Medical Center | Artie Atwood | Episode: Between Dark and Daylight |
| The Name of the Game | Pete | Episode: Cynthia is Alive and Living in Avalon |
| Bracken's World | Gil Dobie | Episode: A Team of One-Legged Acrobats |
| 1971 | Storefront Lawyers | Paul Marek | Episode: This Money Kills Dreams |
| The Birdmen | Orville 'Fitz' Fitzgerald | ABC TV-Movie |
| Nichols | | Episode: The Marrying Fool |
| 1971, 1972, 1975 | Cannon | Dude
Toby Hauser
Sheriff Andrews | Episode: The Salinas Jackpot
Episode: Nobody Beats the House
Episode: The Conspirators |
| 1974 | Get Christie Love! | | Episode: Deadly Betrayal |
| Kolchak: The Night Stalker | Sen. Robert W. Palmer | Episode: The Devil's Platform |
| The Manhunter | | Episode: Flight to Nowhere |
| 1975 | The Last Day | Bill Powers | NBC TV-Movie |
| Barnaby Jones | Darrin Addison | Episode: Image of Evil |
| 1976 | S.W.A.T. | Maynard Hill | Episode: Dragons and Owls |
| Sara | | Episode: 1.9 |
| Alle origini della mafia | Bernardino Campo | ITC Miniseries
Episode: La Speranza |
| 1978 | Baretta | Al Brimmer | Episode: The Appointment |
| Maneaters are Loose! | John Gosford | CBS TV-Movie |
| 1983 | Ryan's Four | Dr. Thomas Ryan | |
| 1984 | Calendar Girl Murders | Lieutenant Dan Stoner | ABC TV-Movie |
| A Touch of Scandal | Father Dwelle | CBS TV-Movie |
| 1986 | Miles to Go... | Stuart Browning | CBS TV-Movie |
| The Hitchhiker | Det. Frank Sheen | Episode: True Believer |
| The Parent Trap II | Bill Grand | ABC TV-Movie |
| The New Twilight Zone | Alex Mattingly | Episode: What Are Friends For? |
| Danger Bay | Don Bared | Episode: The Fish Who Walks |
| 1987 | Poker Alice | Jeremy Collins | CBS TV-Movie |
| 1987, 1988 | Cheers | Evan Drake | Episode: A Kiss is Still a Kiss
Episode: Tale of Two Cuties
Episode: Yacht of Fools
Episode: Let Sleeping Drakes Lie
Episode: The Sam in the Grey Flannel Suit
Episode: Backseat Becky, Up Front |
| 1988 | Moving Target | Joseph Kellogg | NBC TV-Movie |
| Nightmare at Bittercreek | Ding | CBS TV-Movie |
| 1989 | The Heist | Ebbet Berens | HBO TV-Movie |
| Red King, White Knight | Stoner | HBO TV-Movie |
| 1990 | The China Lake Murders | Sheriff Sam Brodie | TV-Movie |
| Child in the Night | Bass | CBS TV-Movie |
| ABC Afterschool Special | Jim | Episode: A Question About Sex |
| She'll Take Romance | Judge Warren Danvers | ABC TV-Movie |
| 1992 | Getting Up and Going Home | Jack Montgomery | TV-Movie |
| In Sickness and In Health | Jarrett Mattison | CBS TV-Movie |
| 1992-1996 | Picket Fences | Sheriff Jimmy Brock | |
| 1997 | Divided by Hate | Steve Riordan | USA TV-Movie |
| Chicago Hope | Jim Kellner | Episode: Guns 'n' Roses |
| What the Deaf Man Heard | Norm Jenkins | CBS TV-Movie |
| 1998 | Two for Texas | Sam Houston | TNT TV-Movie |
| 1999 | Into the Wild Blue | Host | History Documentary |
| The Hunt for the Unicorn Killer | Fred Maddux | NBC Miniseries |
| Aftershock: Earthquake in New York | Thomas Ahearn | CBS TV-Movie |
| 2000 | An American Daughter | Walter | Lifetime TV-Movie |
| High Noon | Will Kane | TBS TV-Movie |
| Jackie Bouvier Kennedy Onassis | Joseph P. 'Joe' Kennedy | CBS TV-Movie |
| 2001 | Chestnut Hill | Daniel Eastman | Unsold TV-Pilot |
| The Voyage to Atlantis: The Lost Empire | Host | Short Documentary |
| 2002 | Path to War | Gen. William Westmoreland | HBO TV-Movie |
| Will & Grace | Dr. Jay Markus | Episode: The Needle and the Omelet's Done |
| 2003 | Biography | Passages Read By | Episode: Jack London - Forces of Nature |
| The West Wing | Sen. Chris Carrick | Episode: Constituency of One |
| 2004 | Homeland Security | Admiral McKee | NBC TV-Movie |
| Law & Order: Special Victims Unit | Judge Oliver Taft | Episode: Poison |
| The Grid | CIA Dep. Director Acton Sandman | TNT Miniseries |
| 2005 | Vinegar Hill | Fritz Grier | CBS TV-Movie |
| Category 7: The End of the World | Col. Mike Davis | CBS Miniseries |
| 2006 | Mammoth | Simon Abernathy | Sci Fi TV-Movie |
| Huff | Ben Huffstodt | Episode: Red Meat
Episode: So...What Brings You to Armageddon?
Episode: Radio Silence |
| Desperation | John Edward Marinville | ABC TV-Movie |
| Fallen | Zeke | ABC Miniseries |
| 2006–2008 | Brothers & Sisters | William Walker | |
| 2007 | Killer Wave | Victor Bannister | Miniseries |
| The Dead Zone | Herb Smith | Episode: Denouement |
| 2008 | Tim And Eric Awesome Show, Great Job! | Himself | |
| Dr. Jekyll and Mr. Hyde | Gabe Utterson | TV-Movie |
| The Trojan Horse | President Stanfield | CBC Miniseries |
