The Gary Moore Show (4 episodes 1962–1964) as himself
McHale's Navy (Season 4, Episode 25) as Lt. Pratt
The Joey Bishop Show (TV series) (1961–1965) (1 episode 1964) as Barney Fife
The Red Skelton Show (TV series) (5 episodes 1951–1971), (1961–1965) as Commodore of Lagoons / 'Steady Fingers' Ferguson / Horaces Horatio / Mr. Pallid / Herbie
The Andy Griffith Show (1960–1968) as Barney Fife
The New Steve Allen Show (1961–1963) as Regular
The Jerry Lewis Show (1 episode 1963) as Himself
38th Academy Awards (1966) (TV) himself co-presenter
The Don Knotts Special (1967) (TV) himself host/performer
The Hollywood Palace (1 episode #7.17 1970) as Himself
The Don Knotts Show (1970–1971) as Himself - Host
Don Knotts' Nice Clean, Decent, Wholesome Hour (1970) as Himself - Host / Performer
The Man Who Came to Dinner (1972) as Dr. Bradley
The New Scooby-Doo Movies (2 episodes 1972) (TV) as Himself (voice)
The Flip Wilson Show (1970–74) (TV) (2 episodes 1972–1973) as Himself
Dinah Shore: In Search of the Ideal Man (1973) (TV) as Himself
I Love a Mystery (1973) as Alexander Archer
Here's Lucy (TV series) (1968–1974) (1 episode 1973) as Ben Fletcher
Hollywood Squares (4 episodes, 1974–1977) as Himself - Panelist
Steve Allen's Laugh Back (1975)
The Captain & Tennille Show (1976-1977) as Himself (recurring guest)
The Muppet Show (1977)
Las Himself - Special Guest Star
Fantasy Island (1978–1979) as Felix Birdsong / Stanley Scheckter
The Love Boat (1979) as Herb Grobecker / Devon King
Three's Company (1979–1984) as Ralph Furley
George Burns Comedy Week (1985) as Himself
Return to Mayberry (1986) as Barney Fife
What a Country! (1987) as F. Jerry 'Bud' McPherson
The Little Troll Prince (1987) as Professor Nidaros (voice)
Matlock (1987–1992) as Les Calhoun
Newhart (TV series) (1982–1990) (1 episode Iron 1990) as Iron
Timmy's Gift: A Precious Moments Christmas (1991) as Titus (voice)
Andy Griffith Show Reunion (1993) (TV) as Himself
Burke's Law (1 episode 1994)
Step by Step (TV series) (1991–1998) (1 episode 1993) as Deputy Feif
101 Dalmatians: The Series (TV series) (2 episodes, 1997-1998) as Additional Voices (voice)
E! True Hollywood Story (1 episode 1998) as Himself
Late Night with Conan O'Brien (1 episode 1999) as Himself
Jingle Bells (1999) as Kris (voice)
Quints (2000) as Gov. Healy
Inside TV Land: The Andy Griffith Show (2000) as Himself
Biography TV Documentary (1987–present) (2 episodes 2000–2002) as Himself
Biography John Ritter: In Good Company (2002) as Himself
Inside TV Land: Cops on Camera (2002) as Himself
Odd Job Jack (2003) as Dirk Douglas
8 Simple Rules (2003) as Himself
Larry King Live (TV series) (1985–2010) (1 episode 2003) as Himself
The Andy Griffith Show Reunion Back to Mayberry (2003) (TV) as Himself / Barney Fife
TV Lands Top Ten (2004) (1 episode) as Himself
Johnny Bravo (cartoon series), episode "Johnny Makeover" (2004) as Don Knotts (voice)
That '70s Show (2005) as The Landlord
Las Vegas (2005) as Himself
The 3rd Annual TV Land Awards (2005) (TV) as Paul Young (segment "Desperate Classic Housewives")
Robot Chicken (cartoon series) (2005) as Himself
Hatching Chicken Little (2006) as Himself
CMT: The Greatest - 20 Greatest Country Comedy Shows (2006) as Himself