| Year | Show | Role | Notes | Ref(s) |
| 1956–1957 | Studio One in Hollywood | Sergeant Joe Capriotti / Hugh | 2 episodes | |
| 1957 | The Big Story | Tyler | Episode: "The Hoax" | |
| 1959 | Armstrong Circle Theatre | Pfc. Elwood Johnson | Episode: "Thunder Over Berlin" | |
| 1962 | The Defenders | Sergeant Wysenski | Episode: "The Empty Chute" | |
| General Electric Theater | Harold | Episode: "Acres and Pains" | |
| 1964 | Brenner | Chris Zelco | Episode: "The Plain Truth" | |
| 1964–1965 | Linus the Lionhearted | | 3 episodes | |
| 1966–1978 | The Mike Douglas Show | Himself | 40 episodes | |
| 1967–1973 | The Tonight Show Starring Johnny Carson | 14 episodes | |
| 1969 | That's Life | Episode: "Our First Fight" | |
| 1971–1972 | The Courtship of Eddie's Father | Mr. Landon / Paul Sterling | 2 episodes | |
| 1971–1973 | Love, American Style | Leonard Ferguson / Harry | 2 episodes | |
| 1972 | The Carol Burnett Show | Himself | Episode: "#6.8" | |
| 1972–1973 | The Paul Lynde Show | Barney Dickerson | 4 episodes | |
| 1975–1976 | Joe and Sons | Gus Duzik | 14 episodes | |
| 1976 | Phyllis | Burt Hillman | Episode: "Phyllis and the Jumper" | |
| Rhoda | Lloyd Zimmer | Episode: "A Touch of Classy" | |
| 1979 | Time Express | Edward Chernoff | Episode: "Garbage Man/Doctor's Wife" | |
| 1979–1983 | The Love Boat | Harlan Weatherly / Tony Vitelli / Bud Hanrahan | 3 episodes | |
| 1980–1982 | Archie Bunker's Place | Carmine | 2 episodes | |
| 1981 | Madame X | Burt Orland | Television film | |
| Hart to Hart | Myron Finkle | Episode: "Murder Takes a Bow" | |
| Private Benjamin | Sgt. Muldoon | Episode: "So Long, Sergeant Ross" | |
| 1982 | Simon & Simon | Harold Traxler | Episode: "The Uncivil Servant" | |
| Alice | Gordy | Episode: "Do You Take This Waitress" | |
| 1983 | Reading Rainbow | Dinosaur Comic | Episode: "Digging Up Dinosaurs" | |
| Amanda's | Sal | Episode: "You Were Meant for Me" | |
| The Other Woman | Mel Binns | Television film | |
| 1984 | Trapper John, M.D. | Artie Merrow | Episode: "Where There's a Will" | |
| 1985 | The Equalizer | Brahms | Episode: "The Equalizer" (Pilot) | |
| Tales from the Darkside | Luther Mandrake | Episode: "The Devil's Advocate" | |
| 1986 | Screen Two | Marty de Reske | Episode: "The McGuffin" | |
| 1987 | Saturday Night Live | Stu | Episode: "Charlton Heston/Wynton Marsalis" | |
| 1988–1989 | Tattingers | Sid Wilbur | 14 episodes | |
| 1989 | Murder, She Wrote | SFPD Lt. Birnbaum | Episode: "When the Fat Lady Sings" | |
| 1990 | Monsters | Victor | Episode: "One Wolf's Family" | |
| Sweet 15 | Waterman | Television film | |
| 1991 | American Playhouse | Sam / Seymour Shapir | 2 episodes | |
| Women & Men 2 | Irving | Television film | |
| 1992–1996 | Law & Order | Michael Tobis / Sam Pokras | 2 episodes | |
| 1993–1998 | Seinfeld | Frank Costanza | 26 episodes | |
| 1993 | Law | Nat Pincus | Episode: "Rhyme and Punishment" | |
| 1994 | In the Heat of the Night | Rabbi Feldman | Episode: "The Rabbi" | |
| 1995 | Homicide: Life on the Street | McGonnigal | Episode: "In Search of Crimes Past" | |
| 1996 | Deadly Games | Phil Cullen | Episode: "Dr. Kramer" | |
| 1997 | Subway Stories | Old Man | Television film | |
| 1998 | Touched by an Angel | Maury Salt | Episode: "Cry and You Cry Alone" | |
| The Larry Sanders Show | Himself | Episode: "I Buried Sid" | |
| Hercules | Eagle | Voice; Episode: "Hercules and the Promethus Affair" | |
