| Year |
Title |
Role |
Other notes |
| 1973 |
Ozzie's Girls |
The Candidate |
|
| 1975 |
Emergency! |
Officer Dave Gordon |
Episode: "905-Wild" |
| Adam-12 |
Officer Gus Corbin |
Episode: "Gus Corbin" |
| Police Woman |
Paul Donin |
Episode: "No Place to Hide" |
| 1976 |
Laverne & Shirley |
Victor, Jeep Buyer |
Episode: "Dating Slump" |
| All's Fair |
|
Episode: "Jealousy" |
| Police Woman |
Stansky |
Episode: "Tender Soldier" |
| Delvecchio |
Ronnie Striker |
Episode: "Hot Spell" |
| 1977 |
Eleanor and Franklin: The White House Years |
Robert Dunlap |
TV movie
Nominated — Primetime Emmy Award for Outstanding Supporting Actor – Miniseries or a Movie |
| The Hardy Boys/Nancy Drew Mysteries |
Chip Garvey |
Episode: "Mystery of the Solid Gold Kicker" |
| 1978 |
Sam |
Officer Mike Breen |
7 episodes |
| Getting Married |
Howie Lesser |
TV movie |
| Little Mo |
Norman Brinker |
TV movie |
| Comes a Horseman |
Billy Joe Meynert |
|
| 1978–1979 |
Centennial |
Captain John McIntosh |
3 episodes |
| 1979 |
Beyond the Poseidon Adventure |
Larry Simpson |
|
| 1979–1983 |
The Love Boat |
Doug Bradbury |
3 episodes |
| 1979–1980 |
240-Robert |
Deputy Dwayne "Thib" Thibideaux |
Main character, 13 episodes |
| 1980 |
Flamingo Road |
Fielding "Field" Carlyle |
TV movie |
| The Dream Merchants |
Johnny Edge |
|
| 1981 |
Goliath Awaits |
Peter Cabot |
TV movie |
| 1981–1982 |
Flamingo Road |
Fielding "Field" Carlyle |
Main character, 37 episodes |
| 1983 |
Doctor in Paradise |
Tommy |
|
| 1983–1986 |
St. Elsewhere |
Dr. Robert Caldwell |
Main character, 70 episodes |
| 1984 |
Tuareg - The Desert Warrior |
Gacel Sayah |
|
| 1986 |
Prince of Bel Air |
Robin Prince |
TV movie |
| The Deliberate Stranger |
Ted Bundy |
TV movie
Nominated — Golden Globe Award for Best Actor – Miniseries or Television Film |
| Let's Get Harry |
Harry Burck, Jr. |
|
| 1987 |
Moonlighting |
Sam Crawford |
4 episodes |
| Summer School |
Freddy Shoop |
|
| After the Promise |
Elmer Jackson |
TV movie
Nominated — Golden Globe Award for Best Actor – Miniseries or Television Film |
| 1988 |
The Presidio |
Jay Austin |
|
| Stealing Home |
Billy Wyatt |
|
| 1989 |
Sweet Bird of Youth |
Chance Wayne |
TV movie |
| Worth Winning |
Taylor Worth |
|
| 1990 |
Till There Was You |
Frank Flynn |
|
| Kenny Rogers Classic Weekend |
Himself |
|
| 1991 |
Dillinger |
John Dillinger |
TV movie |
| Fourth Story |
David Shepard |
TV movie |
| Long Road Home |
Ertie Robertson |
TV movie |
| Shadow of a Doubt |
Uncle Charlie Oakley |
|
| Cold Heaven |
Alex Davenport |
|
| 1991–1993 |
Reasonable Doubts |
Detective Dicky Cobb |
Main character, 45 episodes
Nominated — Golden Globe Award for Best Actor – Television Series Drama (1991)
Nominated — Golden Globe Award for Best Actor – Television Series Drama (1992) |
| 1993 |
Harts of the West |
Rodeo clown |
Episode: "The Right Stuff" |
| 1994 |
Natural Born Killers |
Uncredited |
|
| 1994 |
Wyatt Earp |
Sheriff John Behan |
|
| 1995 |
Original Sins |
Johnathan Franye |
TV movie |
| Magic in the Water |
Jack Black |
|
| The Last Supper |
Dominant Male |
|
| Charlie Grace |
Charlie Grace |
Main character, 6 episodes |
| Acts of Contrition |
Jonathan Frayne |
Movie |
| 1996 |
Strangers |
Mark |
Episode: "Visit" |
| 1996–2000 |
Chicago Hope |
Dr. Jack McNeil |
Main character, 95 episodes
Nominated — Screen Actors Guild Award for Outstanding Performance by an Ensemble in a Drama Series (1996)
Nominated — Screen Actors Guild Award for Outstanding Performance by an Ensemble in a Drama Series (1997) |
| 1997 |
Adventures from the Book of Virtues |
Ulysses |
Episode: "Perseverance" |
| Casualties |
Tommy Nance |
|
| The First to Go |
Jeremy Hampton |
|
| 1998 |
From the Earth to the Moon |
Wally Schirra |
Episode: "We Have Cleared the Tower" |
| Fear and Loathing in Las Vegas |
Magazine Reporter at Mint 400 |
|
| 1999 |
I'll Remember April |
John Cooper |
|
| 2000 |
For All Time |
Charles Lattimer |
|
| The Amati Girls |
Lawrence |
|
| 2001 |
Crossfire Trail |
Bruce Barkow |
|
| And Never Let Her Go |
Thomas Capano |
TV movie |
| The Legend of Tarzan |
Bob Markham (voice) |
Episode: "Tarzan and the Outbreak" |
| 2002 |
Local Boys |
Jim Wesley |
|
| The West Wing |
Special Agent Simon Donovan |
4 episodes
Nominated — Primetime Emmy Award for Outstanding Guest Actor – Drama Series |
| 2003 |
JAG |
Special Agent Leroy Jethro Gibbs |
2 episodes (NCIS pilot episodes) |
| Freaky Friday |
Ryan |
|
| 2003–present |
NCIS |
Special Agent Leroy Jethro Gibbs |
Current main character, every episode
Nominated — People's Choice Award – Favorite TV Drama Actor (2010)
Nominated — People's Choice Award – Favorite TV Drama Crime Fighter (2011) |
| 2004 |
Chasing Liberty |
President James Foster |
|
| 2009 |
Weather Girl |
Dale |
|
| 2010 |
Justice League: Crisis on Two Earths |
Superman (voice) |
Direct-to-DVD release |
| 2011 |
John Sandford's Certain Prey |
Deputy Police Chief Lucas Davenport |
TV movie |
| 2012 |
Family Guy |
NCIS Agent (voice) |
Season 10 Episode 13 Tom Tucker: The Man and His Dream (Cutaway) |
