| Kissyfur | September 13, 1986 | NBC | 46 |
| Kite Man: Hell Yeah! | July 18, 2024 | HBO Max | 10 |
| Kitti Katz | May 18, 2023 | Netflix | 10 |
| Kiya & the Kimoja Heroes | March 22, 2023 | Disney Jr. | 26 |
| Klondike Kat | September 10, 1966 | — | 26 |
| Klump | 2018 | — | — |
| Klutter! | September 9, 1995 | Fox Broadcasting Company, Fox Kids | 8 |
| Knights of the Zodiac: Saint Seiya | July 19, 2019 | Netflix | 24 |
| Koala Man | January 9, 2023 | Hulu | 8 |
| Koki | 1997 | — | — |
| Kong: King of the Apes | April 15, 2016 | Netflix | 23 |
| Kong: The Animated Series | May 26, 2001 | Fox Kids | 40 |
| Krapopolis | September 24, 2023 | Fox Broadcasting Company | 58 |
| Krypto the Superdog | March 25, 2005 | Cartoon Network | 39 |
| Kung Fu Panda: Legends of Awesomeness | September 19, 2011 | Nickelodeon | 80 |
| Kung Fu Panda: The Dragon Knight | July 14, 2022 | Netflix | 42 |
| Kung Fu Panda: The Paws of Destiny | 2018 | Amazon Prime Video | 26 |
| Kuu Kuu Harajuku | November 1, 2015 | Nickelodeon, Nick Jr. Channel, 10 Comedy | 78 |
| Lady Lovely Locks | April 4, 1987 | — | 20 |
| Laff-A-Lympics | September 10, 1977 | American Broadcasting Company | 24 |
| Lalaloopsy | March 29, 2013 | Nickelodeon, Nick Jr. Channel | 52 |
| Larryboy: The Cartoon Adventures | March 16, 2002 | — | 4 |
| Lassie's Rescue Rangers | November 11, 1972 | American Broadcasting Company | 16 |
| Laurel and Hardy | September 10, 1966 | Broadcast syndication | 156 |
| Laverne & Shirley | October 10, 1981 | American Broadcasting Company | 13 |
| Lazor Wulf | April 7, 2019 | Adult Swim, Cartoon Network | — |
| Legend of the Three Caballeros | June 9, 2018 | — | 13 |
| Legends of Bikini Bottom | January 28, 2011 | Nickelodeon | 6 |
| Legion of Super Heroes | September 23, 2006 | The CW, Kids' WB | 26 |
| Lego Bionicle: The Journey to One | March 4, 2016 | — | — |
| Lego City Adventures | 2019 | Nickelodeon | 26 |
| Lego Elves: Secrets of Elvendale | September 1, 2017 | — | — |
| Lego Marvel Avengers: Strange Tails | November 14, 2025 | Disney+ | 2 |
| LEGO Marvel short films | 2013 | — | 10 |
| Lego Nexo Knights | December 18, 2015 | Cartoon Network | 40 |
| Lego One Piece | September 29, 2026 | — | 2 |
| Lego Star Wars: Droid Tales | July 6, 2015 | Disney XD | 5 |
| Lego Star Wars: Rebuild the Galaxy | September 13, 2024 | — | 4 |
| Lego Star Wars: The Freemaker Adventures | June 20, 2016 | Disney XD | 26 |
| Lego Star Wars: The Resistance Rises | — | Disney XD | 5 |
| Lego Star Wars: The Yoda Chronicles | — | Cartoon Network | — |
| Let's Go Luna! | November 21, 2018 | TVOKids, PBS Kids, Knowledge Kids | 64 |
| Liberty's Kids | September 2, 2002 | PBS | 40 |
| Life with Louie | December 18, 1994 | Fox Broadcasting Company | 39 |
| Like, Share, Die | January 29, 2015 | — | 16 |
| Lil' Bush | June 13, 2007 | Comedy Central | 17 |
| Lilly the Witch | September 4, 2004 | CBBC | 52 |
| Lilo & Stitch: The Series | September 20, 2003 | Disney Channel | 65 |
| Linus the Lionhearted | September 26, 1964 | CBS | 39 |
| Lippy the Lion & Hardy Har Har | September 3, 1962 | Broadcast syndication | 52 |
| Liquid Television | June 2, 1991 | MTV | 27 |
| Little Bill | November 28, 1999 | Nickelodeon, Nick Jr., BET | 127 |
| Little Charmers | January 12, 2015 | Nick Jr. Channel | 40 |
| Little Demon | August 25, 2022 | FX | 10 |
| Little Dracula | September 3, 1991 | — | 26 |
| Little Einsteins | October 9, 2005 | Playhouse Disney, Disney Channel | 67 |
| Little Ellen | September 13, 2021 | — | 20 |
| Little Mouse on the Prairie | 1997 | Freeform | 26 |
| Little Rosey | September 8, 1990 | American Broadcasting Company | 13 |
| Little Shop | September 7, 1991 | Fox Broadcasting Company | 13 |