| Kapitan Bomba | — | 4fun.tv | 164 |
| Kappa no Kaikata | October 4, 2004 | — | 26 |
| Kappamaki | March 31, 2003 | — | 130 |
| Kaput & Zösky | September 2, 2002 | Nicktoons | 26 |
| Karakuri Circus | October 11, 2018 | Tokyo MX, Nippon BS Broadcasting | 36 |
| Karaoke Senshi Mike Jirō | April 4, 1994 | NHK Satellite 2 Television | 20 |
| Karas | March 25, 2005 | — | 6 |
| Karasu Tengu Kabuto | July 29, 1990 | — | 39 |
| Karate Kommandos | September 15, 1986 | Boomerang | 5 |
| Karate Master | October 3, 1973 | — | 47 |
| Kare Kano | October 2, 1998 | TV Tokyo | 26 |
| Kargin Multer | — | — | — |
| Karin | November 4, 2005 | WOWOW | 24 |
| Karl to Fushigi na Tō | October 8, 2010 | Kids Station | 26 |
| Karlsson on the Roof | 2002 | SVT1 | 26 |
| Karma's World | October 15, 2021 | Netflix | — |
| Karneval | April 3, 2013 | — | 13 |
| Kasei Yakyoku | March 25, 1989 | — | 4 |
| Kashimashi: Girl Meets Girl | January 11, 2006 | — | 12 |
| Kassai and Luk | April 30, 1997 | France 2 | 26 |
| Kasumin | October 13, 2001 | NHK Educational TV | — |
| Kasztaniaki | — | TVP2 | — |
| Katana Maidens: Toji No Miko | January 5, 2018 | — | 24 |
| Katanagatari | January 26, 2010 | — | 12 |
| Kate & Mim-Mim | September 1, 2014 | CBeebies, BBC Kids, Knowledge Kids | 49 |
| Katie and Orbie | 1994 | Family Channel | 78 |
| Katri, Girl of the Meadows | January 8, 1984 | — | 49 |
| Katsugeki! Touken Ranbu | July 2, 2017 | — | — |
| Katz Fun | — | Cartoon Network | 39 |
| Kawagoe Boys Sing | October 9, 2023 | — | — |
| Kay's Daily Doodles | — | Bilibili | — |
| Kaya-chan Isn't Scary | January 11, 2026 | — | — |
| Kayko and Kokosh | February 28, 2021 | — | 5 |
| Kaze no Shōjo Emily | April 7, 2007 | NHK Educational TV | 26 |
| Kaze no Stigma | April 12, 2007 | — | 24 |
| Kaze no Yojimbo | October 2, 2001 | — | 25 |
| Keep Your Hands Off Eizouken! | January 5, 2020 | NHK General TV | 12 |
| Keijo!!!!!!!! | October 6, 2016 | — | 12 |
| Kekkaishi | October 16, 2006 | Cartoon Network, Nippon Television | 52 |
| Keluang Man | — | TV1 | 142 |
| Keluarga Somat | June 8, 2013 | — | — |
| Kemeko Deluxe! | October 4, 2008 | — | 12 |
| Kemono Friends | January 11, 2017 | TV Tokyo | — |
| Kemono Friends 2 | January 15, 2019 | TV Tokyo | 12 |
| Kemono Jihen | January 10, 2021 | — | 12 |
| Kemono Michi: Rise Up | October 2, 2019 | — | 12 |
| Kemonozume | August 5, 2006 | — | 13 |
| Kemurikusa | January 9, 2019 | Tokyo MX | 12 |
| Kemy Expedition | — | — | — |
| Kengan Ashura | July 31, 2019 | — | 24 |
| Kenichi: The Mightiest Disciple | October 8, 2006 | TV Tokyo | 50 |
| Kenichi: The Mightiest Disciple – The Attack of Darkness | March 14, 2012 | — | 11 |
| Kenka Bancho Otome: Girl Beats Boys | April 12, 2017 | — | 12 |
| Kenkō Zenrakei Suieibu Umishō | July 4, 2007 | — | 13 |
| Kenyū Densetsu Yaiba | April 9, 1993 | TV Tokyo | 52 |
| Kero Kero Chime | March 6, 1997 | — | 30 |
| Keshikasu-kun | January 4, 2010 | TV Tokyo | 44 |
| Ketchup: Cats Who Cook | October 5, 1998 | — | 65 |
| Kevin Spencer | March 1, 1999 | CTV Comedy Channel | 113 |
| Khushi - The Princess of the Jungle | — | — | — |