| Mulligan | May 12, 2023 | Netflix | 10 |
| Mummies Alive! | September 15, 1997 | Broadcast syndication | 42 |
| Muppet Babies | March 23, 2018 | Disney Jr. | 89 |
| Murder Drones | 2021 | YouTube | — |
| My Dad the Bounty Hunter | February 9, 2023 | Netflix | 20 |
| My Favorite Martians | September 8, 1973 | CBS | 16 |
| My Friends Tigger & Pooh | May 12, 2007 | Playhouse Disney, Disney Channel, Disney Jr. | 44 |
| My Gym Partner's a Monkey | December 26, 2005 | Cartoon Network | 52 |
| My Life as a Teenage Robot | August 1, 2003 | Nickelodeon | 40 |
| My Little Pony | September 15, 1986 | Broadcast syndication | 65 |
| My Little Pony Tales | August 2, 1992 | Broadcast syndication | 26 |
| My Little Pony: Friendship Is Magic | October 10, 2010 | Discovery Family, Hub Network | 222 |
| My Little Pony: Make Your Mark | May 26, 2022 | — | 27 |
| My Nezha and Transformers | December 6, 2025 | CCTV-14 Children | 52 |
| My Pet Monster | September 12, 1987 | American Broadcasting Company | 13 |
| Mysticons | August 28, 2017 | Nicktoons, Nickelodeon | 40 |
| Napoleon Dynamite | January 15, 2012 | Fox Broadcasting Company | 6 |
| Natural Habitat | August 10, 2021 | — | — |
| Nature Cat | November 25, 2015 | PBS Kids | 91 |
| Neighbors from Hell | June 7, 2010 | TBS | 10 |
| Neo Yokio | September 22, 2017 | Netflix | 6 |
| New Kids on the Block | September 8, 1990 | Disney Channel | 14 |
| New Looney Tunes | September 21, 2015 | Boomerang, Cartoon Network | 102 |
| New Teen Titans | — | Cartoon Network | 19 |
| NFL Rush Zone | September 6, 2010 | Nicktoons | 65 |
| Ni Hao, Kai-Lan | February 7, 2008 | Nickelodeon | 42 |
| Nightmare Ned | April 19, 1997 | American Broadcasting Company | 25 |
| Niko and the Sword of Light | July 20, 2017 | — | 23 |
| Ninjago | January 14, 2011 | Nickelodeon, Cartoon Network, Cartoon Network, YTV | 160 |
| Ninjago: Dragons Rising | June 1, 2023 | — | 40 |
| Noddy, Toyland Detective | March 26, 2016 | Super RTL, France 5, Universal Kids, Milkshake! | 52 |
| Noodles and Nedd | — | — | — |
| Oddballs | October 7, 2022 | Netflix | 20 |
| Oh Yeah! Cartoons | July 18, 1998 | Nickelodeon | 75 |
| Oishi High School Battle | — | — | 30 |
| OK K.O.! Let's Be Heroes | August 1, 2017 | Cartoon Network | 112 |
| Olivia | January 24, 2009 | Nick Jr. | 37 |
| Oni: Thunder God's Tale | October 21, 2022 | — | 4 |
| Onyx Equinox | November 21, 2020 | Crunchyroll | — |
| Open Season: Call of Nature | November 3, 2023 | Family Channel | — |
| Oswald | August 20, 2001 | Nickelodeon, Treehouse TV, Nick Jr. Channel, Tiny Living | 26 |
| Our Cartoon President | February 11, 2018 | Showtime | 36 |
| Out There | April 19, 2013 | IFC | 10 |
| Over the Garden Wall | November 3, 2014 | Cartoon Network | 10 |
| Ozzy & Drix | September 14, 2002 | The WB | 26 |
| Pac-Man | September 25, 1982 | American Broadcasting Company | 43 |
| Pac-Man and the Ghostly Adventures | June 15, 2013 | Disney XD | 52 |
| Pacific Rim: The Black | March 4, 2021 | Netflix | 14 |
| Paddington Bear | December 2, 1989 | Broadcast syndication | 13 |
| Pandamonium | September 18, 1982 | CBS | 13 |
| Pantheon | September 1, 2022 | AMC+ | 16 |
| Paradise PD | August 31, 2018 | Netflix | 43 |
| Paranormal Action Squad | — | YouTube Premium | 8 |
| Partridge Family 2200 A.D. | September 7, 1974 | CBS | 16 |
| Paw Paws | October 31, 1985 | Broadcast syndication | 21 |
| PB&J Otter | March 15, 1998 | Playhouse Disney, Disney Jr. | 65 |
| Peep and the Big Wide World | April 12, 2004 | TLC, Discovery Kids, TVOKids, PBS Kids | 55 |
| Peg + Cat | October 7, 2013 | PBS, PBS Kids | 63 |
| Penn Zero: Part-Time Hero | December 5, 2014 | Disney XD, Disney XD | 35 |
| Pepper Ann | September 13, 1997 | American Broadcasting Company, Disney Channel, UPN | 65 |