K
- Kym Karath (born 1958)
- Spencer's Mountain (1963) - as Pattie-Cake Spencer
- The Thrill of It All (1963) - as Maggie Boyer
- Good Neighbor Sam (1964) - Denise Bissel
- The Sound of Music (1965) - Gretl von Trapp
- Sarah Rose Karr (born 1984)
- Kindergarten Cop (1990) - as Emma
- Father of the Bride (1991) - as young Annie Banks
- Beethoven (1992) - as Emily Newton
- Beethoven's 2nd (1993) - as Emily Newton
- Omri Katz (born 1976)
- Dallas (1983–1991)
- Eerie, Indiana (1991–1992)
- Hocus Pocus (1993)
- Staci Keanan (born 1975)
- I'll Take Manhattan (1987)
- Lisa (1990)
- My Two Dads (1987–1990)
- Casey's Gift: For Love of a Child (1990)
- Going Places (1990)
- Step by Step (1991–1998)
- Buster Keaton (1895–1966)
- The Three Keatons (1900s)
- Stella Keitel (born 1985)
- Goodfellas' (1990)
- Bad Lieutenant (1992)
- Malcolm David Kelley (born 1992)
- Lost (2004–present)
- You Got Served (2004)
- Antwone Fisher (2002)
- My Name Is Earl (2006)
- Paul Kelly (1899–1956)
- Jimmie's Job (1911)
- Captain Barnacle, Diplomat (1911)
- Billy's Pipe Dream (1912)
- The Fortune Hunters of Hicksville (1913)
- When Glasses Are Not Glasses (1913)
- The Gang (1914)
- Mr. Jarr's Big Vacation (1915)
- The Jarr Family Discovers Harlem (1915)
- Mr Jarr and the Dachshund (1915)
- The Jarrs Visit Arcadia (1915)
- Mr Jarr's Magnetic Friend(1915)
- The Shabbies (1915)
- A Family Picnic (1915)
- Mrtle The Manicurist (1916)
- The Star Spangled Banner (1917)
- Knights of the Square Table (1917)
- Anne of Green Gables (1919)
- Ricky Kelman (born 1950)
- The Dennis O'Keefe Show (1959-1960)
- Our Man Higgins (1962-1963)
- Lance Kerwin (born 1960)
- Amelia Earhart (1976)
- James at 15 (1977)
- Paige and Ryanne Kettner (born 1991)
- Days of our Lives (1994–1998)
- Beverly Hills, 90210 (1994–1995)
- How to Make an American Quilt (1995)
- A Case for Life (1996)
- Nicole Kidman (born 1967)
- Bush Christmas (1983)
- BMX Bandits (1983)
- A Country Practice (1984)
- Kaleena Kiff (born 1974)
- Love, Sidney (1981–1983)
- Still the Beaver (1983)
- Pole Position (1984) (voice)
- The New Leave It to Beaver (1984–1989)
- Popeye and Son (1987) (voice)
- Q'Orianka Kilcher (born 1990)
- How the Grinch Stole Christmas (2000)
- The New World (2005)
- Cammie King (1934–2010)
- Gone with the Wind (1939)
- Bambi (1942) (voice)
- Christina Kirkman (born 1993)
- The Cat in the Hat (2003)
- All That (2005)
- Cody Klop (born 1993)
- Shades of Ray (2006)
- Star Trek (2009)
- Christopher Knight (born 1957)
- The Brady Bunch (1969–1974) - as Peter Brady
- The Brady Kids (1972–1974) (voice)
- Kurt Krakowian (born 1964)
- According to Jim (2 episodes, 2003)
- Saved by the Bell (3 episodes, 1991–1992)
- Cheers (1 episode,1991)
- Days of Our Lives (1 episode, 1986)
- Vega$ (2 episodes, 1979–1981)
- The Love Boat (1 episode, 1978)
- Happy Days (1 episode, 1977)
- Laverne & Shirley (1 episode,1977)
- MTV Spring Break: Lake Havasu (1995) (TV)
- The Special London Bridge Special (1972) (TV)
- Keshia Knight Pulliam (born 1979)
- The Cosby Show (1984–1992)
- The Last Dragon (1985)
- Frederick Koehler (born 1975)
- Mr. Mom (1983)
- Kate & Allie (1984–1989)
- The Pick-up Artist (1987)
- Scott Kolden (born 1962)
- Mystery in Dracula's Castle (1973)
- Charley and the Angel (1973)
- Sigmund and the Sea Monsters (1973–1975) - as Scott Stuart
- A Whale of a Tale (1977)
- The Day Time Ended (1980)
- Mary Kornman (1915–1973)
- Our Gang (1922–1926)
- The Boy Friends (1930–1932)
- Charlie Korsmo (born 1978)
- Men Don't Leave (1990)
- Dick Tracy (1990)
- Heat Wave (1990)
- What About Bob? (1991)
- The Doctor (1991)
- Hook (1991)
- Marisa Kuers (born 1987)
- Barney & Friends (1997–2001)
- Erik Knudsen (born 1988)
- Mental Block (2003–2004)
- Saw II (2005)
- The Prize Winner of Defiance, Ohio (2005)
- Nathan Kress (born 1992)
- House M.D. (2005)
- Shuriken School (2005)
- Notes from the Underbelly (2006)
- Standoff (2006)
- Without a Trace (2007)
- The Suite Life of Zack & Cody (2007)
- iCarly (2007–present)
- Mila Kunis (born 1983)
- That '70s Show (1998)
- Family Guy (1999) - as Meg Griffin
- Katy Kurtzman (born 1965)
- Beat the Turtle Drum (1977)
- Mulligan's Stew (1977)
- The Awakening Land (1978)
- When Every Day Was the Fourth of July (1978)
- Child of Glass (1978)
- Hunters of the Reef (1978)
- The New Adventures of Heidi (1978)
- Long Journey Back (1978)
- Donovan's Kid (1979)
- Sex and the Single Parent (1979)
- Diary of a Teenage Hitchhiker (1979)
- Dynasty (1981)
Read more about this topic: List Of Former Child Actors From The United States