| Year | Title | Role | Notes |
| 1973 | Emergency! | Hamburger-Eating Teen | Episode: "Inheritance Tax"
Uncredited |
| 1974 | The Waltons | Tyler Crofut | Credited as Rob Clotworhy
Episode: "The Graduation" |
| Columbo | Boodle Boy / Jonathan B. Miller | Episode: "By Dawn's Early Light" |
| Police Woman | The Gas Jockey | Credited as Rob Clotworthy
Episode: "Shoefly" |
| 1975 | ABC Afterschool Special | Clete | Episode: "The Skating Rink" |
| 1976 | The Cheerleaders | BJ's Boyfriend | Television Film |
| Black Sheep Squadron | Lt. Wyatt | Credited as Rob Clotworthy
Episode: "Prisoners of War" |
| 1977 | Police Story | Corvette Driver | Credited as Rob Clotworthy
Episode: "Stigma" |
| 1978 | The Rockford Files | Tommy | Episode: "South by Southeast" |
| M*A*S*H | Private Welch | Episode: "Dear Comrade" |
| 1979 | Billy | Gary | Episode: "Fathers and Sons" |
| 1980 | Stone | The Runner | Episode: "Death Run" |
| 1981 | Death of a Centerfold: The Dorothy Stratten Story | Floyd | Television Film |
| Dynasty | Ty Meredith | Episode: "The Verdict" |
| 1982 | Star of the Family | Bigelow | Episode: "Pilot" |
| 1983 |
Ghost Dancing | Water Deliveryman | Television Film |
| Whiz Kids | Arbus | Episode: "Candidate for Murder" |
| 1984 | Three's Company | Tony Williams / Tony | 2 episodes |
| Shattered Vows | Mark | Television film |
| Sweet Revenge | Cashier | Television film; uncredited |
| Fatal Vision | MP Sergeant | Miniseries; 2 episodes |
| 1985 | Remington Steele | Paul Stuban | Episode: "Illustrated Steele" |
| George Burns Comedy Week | Actor | Episode: "The Dynamite Girl" |
| The New Leave It to Beaver | Mr. Newhouse | Episode: "Wow" |
| 1986 | The Colbys | Attorney | Episode: "The Trial"
Uncredited |
| Outlaws | Mr. Harrison | Episode: "Outlaws" |
| 1986–1987 | Falcon Crest | Mark | 2 episodes |
| 1987 | Dennis the Menace | Tom | Television film |
| 1988 | 1st & Ten | Marshall | Episode: "The Inmates Buy the Asylum" |
| 1989 | Hunter | Kevin | 4 episodes |
| 1990 | Matlock | Prosecutor in Los Angeles | Episode: "Nowhere to Turn" |
| Father Dowling Mysteries | Olsen | Episode: "The Showgirl Mystery" |
| Who's the Boss? | Greg | Episode: "Parental Guidance Suggested" |
| 1991 | True Colors | Danforth | 2 episodes |
| Murphy Brown | Allen | Episode: "Hoarse Play" |
| 1992 | Tequila and Bonetti | Lloyd | Episode: "A Perfect Match" |
| Herman's Head | Frank | Episode: "Stop Me Before I Help Again" |
| 1993 | Doogie Howser, M.D. | Dr. Bob Whitman | Episode: "The Adventures of Sherlock Holmes" |
| Batman: The Animated Series | Billy (voice) | Episode: "Mudslide"; credited as Bob Clotworthy[10] |
| 1994 | Boy Meets World | TV Voice | Episode: "The B-Team of Life" |
| 1995–2006 | The Young and the Restless | Judge Russell Jennings / Greg Hillman | 43 Episodes |
| 1996 | Murphy Brown | Dole Operative | Episode: "The Bus Stops Here" |
| Crime of the Century | Reporter | Television Film |
| Melrose Place | Auctioneer | Episode: "Crazy Love" |
| 1997 | Get to the Heart: The Barbara Mandrell Story | Dr. Newton Louvern | Television Film |
| 1998 | The New Batman Adventures | Pilot (voice) | Episode: "The Ultimate Thrill"[10] |
| 1999 | The Practice | Medical Expert | Episode: "Oz" |
| The Hand Behind the Mouse: The Ub Iwerks Story | Ub Iwerks (voice) | Documentary |
| 2000 | JAG | Jim Wythrip | Episode: "The Witches of Gulfport" |
| The Drew Carey Show | INS Inspector | Episode: "Drew and the Trail Scouts" |
| 2001 | The West Wing | Tom | Episode: "The Drop In" |
| Mahô shôjo neko Taruto | Rakugan (voice) | English dub |
| Raptor | Doctor | Television film |
| 2003 | Boston Public | Radio Host | Episode: "Chapter Fifty-Nine" |
| Miracles | Steve Jones | Episode: "Hand of God" |
| The Practice | Judge Tyler Flynn | Episode: "Cause of Action" |
| 2004 | Phil of the Future | Dr. Gennaro | Episode: "Daddy Dearest" |
| NYPD Blue | Roger | Episode: "Bale Out" |
| Empire of Dreams: The Story of the Star Wars Trilogy | Narrator | Documentary |
| 2005 | Hercules | Narrator | 2 episodes |
| 2005–2010 | Medium | News Reporter / Ripley's Believe It or Not Announcer / Bradley Campaign Ad Announcer | 3 episodes; uncredited |
| 2006 | That '70s Show | Customer | Episode: "My Fairy King" |
| Criminal Minds | Don Norvell | Episode: "Aftermath" |
| The Water is Wide | Narrator | Television film |
| 2006–2012 | Two and a Half Men | Gangster #1 / Pilot / TV Commercial Announcer / TV Commercial Narrator / TV Announcer | 11 episodes |
| 2007 | The Riches | Clay Wilkes | Episode: "Believe the Lie" |
| Boston Legal | Zachary West | Episode: "Beauty and the Beast" |
| Bone Eater | Jimmy Winger | Television film |
| Judy's Got a Gun | Roger Yeager | Television film |
| Real Premonitions | Narrator | Documentary |
| Star Wars: The Legacy Revealed | Narrator | Documentary |
| 2007–2008 | Days of Our Lives | Dean Randall Lochlan | 3 episodes |
| 2008 | The Batman | Arkham Asylum Warden (voice) | Episode: "What Goes Up..."; credited as Bob Clotworthy[10] |
| Indiana Jones and the Ultimate Quest | Narrator | Documentary |
| Batman Unmasked | Narrator | Documentary |
| Valkyrie: The Plot to Kill Hitler | Narrator | Documentary |
| 2008–2015 | The Big Bang Theory | Astronaut, Announcer, Dave Roeger, Headmaster Edwards, Train Conductor | Recurring role |
| 2009–2020 | Ancient Aliens | Narrator | 190 episodes |
| 2010 | Sonny with a Chance | Dr. Spector | Episode: "Walk a Mile in My Pants" |
| Batman: Under the Red Hood | Leo / Thug | Television film |
| All My Children | Minister | Episode: "#1.10431" |
| 2011 | Big Love | Elder Mccrackle | Episode: "The Special Relationship" |
| The Defenders | Bennett Perkins | Episode: "Nevada v. Hunter" |
| Eagleheart | Stan | Episode: "Chris, Susie, Brett and Malice" |
| The Mentalist | Pulaski | Episode: "Blood for Blood" |
| 2012 | The Mentalist | Rudolph Pulaski | Episode: "At First Blush" |
| Diagnosis: Dead or Alive | Kurt | Episode: "Jamie & David" |
| 2013 | Broken Quest | Adventure Master | Episode: "The Adventure Master" |
| China, IL | Carabas, Kevin Costner (voice) | 2 episodes |
| 2014 | Falling Skies | The Monk | 3 episodes |
| Sinkholes: Swallowed Alive | Narrator | Documentary |
| Cesar Millan: Love My Pit Bull | Narrator | Documentary |
| We the Economy: 20 Short Films You Can't Afford to Miss | Narrator | Documentary |
| 2014–present | The Curse of Oak Island | Narrator | 111 episodes |
| 2015 | Beautiful & Twisted | Senior Bank Manager | Television film |
| Switched at Birth | Professor Epstein | Episode: "The Player's Choice" |
| Blood and Glory: The Civil War in Color | Narrator | Miniseries |
| 2016 | Better Call Saul | Spokesperson - Davis & Main TV Commercial | 2 episodes |
| Ultimate Spider-Man | Captain George Stacy (voice) | Episode: "Return to the Spider-Verse"[10] |
| 2017 | We Bare Bears | Warren (voice) | Episode: "Neighbors" |
| Groomzilla | Ed Rydell | Television film |
| 2018–2019 | The Curse of Civil War Gold | Narrator | 16 episodes |
| 2019 | Vanished | Narrator | Television film |
| Young Sheldon | Mayor Harrison | Episode: "A Political Campaign and a Candy Land Cheater" |
| 2020 | Homeland | Judge | Episode: "The English Teacher" |
| 2020–present | The Secret of Skinwalker Ranch | Narrator | 44 episodes |
| 2023 | Pluto | Johannsen (voice) | English dub; 2 episodes[10] |
