| Kino's Journey | April 8, 2003 | WOWOW | 13 |
| Kino's Journey: The Beautiful World - The Animated Series | October 6, 2017 | — | 12 |
| Kinokoinu: Mushroom Pup | October 3, 2024 | — | 12 |
| Kinpatsu no Jeanie | July 19, 1979 | TV Tokyo | 13 |
| Kipo and the Age of Wonderbeasts | January 14, 2020 | Netflix | 30 |
| Kipper | September 5, 1997 | Walt Disney Television | 78 |
| KiraKira Pretty Cure a la Mode | February 5, 2017 | — | 49 |
| Kirarin Revolution | April 7, 2006 | TV Tokyo | 153 |
| Kiratto Pri Chan | April 8, 2018 | TX Network | — |
| Kirby: Right Back at Ya! | October 6, 2001 | CBC Television Co. | 100 |
| Kiri and Lou | — | — | — |
| Kirio Fan Club | April 2, 2026 | — | 12 |
| Kishin Houkou Demonbane | May 18, 2006 | WOWOW | 12 |
| Kishin Taisen Gigantic Formula | April 4, 2007 | — | — |
| Kiss Him, Not Me | October 6, 2016 | TBS Television | 12 |
| Kissyfur | September 13, 1986 | NBC | 46 |
| Kiss×sis | December 22, 2008 | — | 12 |
| Kiss×sis | April 4, 2010 | — | 12 |
| Kite Man: Hell Yeah! | July 18, 2024 | HBO Max | 10 |
| Kiteretsu Daihyakka | March 27, 1988 | Fuji Television | 331 |
| Kitti Katz | May 18, 2023 | Netflix | 10 |
| Kiya & the Kimoja Heroes | March 22, 2023 | Disney Jr. | 26 |
| Kiyo in Kyoto | February 25, 2021 | NHK Educational TV, NHK World-Japan | 12 |
| Kiznaiver | April 9, 2016 | Tokyo MX, Gunma Television | — |
| Kizuna no Allele | April 4, 2023 | — | 24 |
| Kizuna: Bonds of Love | — | — | — |
| Kleine Isar | November 8, 1980 | Nederlandse Christelijke Radio Vereniging | 18 |
| Kleiner Dodo | 2007 | — | 26 |
| Klondike Kat | September 10, 1966 | — | 26 |
| Klump | 2018 | — | — |
| Klutter! | September 9, 1995 | Fox Broadcasting Company, Fox Kids | 8 |
| Knight's & Magic | July 2, 2017 | — | 13 |
| Knights of Guinevere | September 19, 2025 | Glitch Productions | — |
| Knights of Sidonia | April 11, 2014 | — | 24 |
| Knights of the Zodiac: Saint Seiya | July 19, 2019 | Netflix | 24 |
| Knyacki! | — | NHK Educational TV | — |
| Koala Man | January 9, 2023 | Hulu | 8 |
| Koala's Diary | October 2025 | — | — |
| Kobato | October 6, 2009 | NHK Satellite 2 Television | 24 |
| Kobo, the Li'l Rascal | October 19, 1992 | Nippon Television | 63 |
| Kocchi Muite! Miiko | February 14, 1998 | TV Asahi | 42 |
| KochiKame: Tokyo Beat Cops | 1996 | — | 367 |
| Kochoki | July 8, 2019 | — | 12 |
| Kodocha | April 5, 1996 | TV Tokyo | 102 |
| Kodomo no Jikan | October 12, 2007 | — | 12 |
| Kogepan | November 5, 2001 | — | 10 |
| Koi Kaze | April 1, 2004 | — | 13 |
| Koi Koi Seven | April 4, 2005 | — | 13 |
| Koi suru Tenshi Angelique | July 8, 2006 | — | — |
| Koihime Musō | July 9, 2008 | — | — |
| Koikimo | April 5, 2021 | — | 12 |
| Koishi Komeiji's Heart-Throbbing Adventure | June 28, 2009 | — | — |
| Koisuru One Piece | — | — | — |
| Koki | 1997 | — | — |
| Kokkoku | January 8, 2018 | — | 12 |
| Kokoro Connect | July 8, 2012 | — | 13 |
| Kokoro Connect: Michi Random | November 19, 2012 | — | 4 |
| Kokoro Library | October 12, 2001 | — | 13 |
| Kom We Gaan | January 2, 2005 | VPRO | 11 |
| Komekami! Girls | April 8, 2026 | — | 12 |