- Obake Zukan
- Oban Star-Racers
- Obsolete
- Occult Academy
- Occultic;Nine
- Ocean Waves
- Oda Cinnamon Nobunaga
- Oda Nobuna No Yabou
- Oedo wa Nemurenai!
- Oh! Edo Rocket
- Oh! Family
- Oira Uchuu no Tankoufu (Dub)
- Oishinbo
- Oishinbo: Kyuukyoku tai Shikou, Chouju Ryouri Taiketsu!!
- Oishinbo: Nichibei Kome Sensou
- Ojamajo Doremi
- Ojamajo Doremi Dokkaan!
- Ojamajo Doremi Sharp
- Ojamajo Doremi Sharp Movie
- Ojamajo Doremi: Owarai Gekijou
- Ojiisan no Lamp
- Ojisan to Marshmallow
- Okoshiyasu, Chitose-chan
- Okusama ga Seitokaichou!
- Okusama ga Seitokaichou! OVA
- Okusama ga Seitokaichou!+!
- Olympia Kyklos
- Omae Umasou da na
- Omae wa Mada Gunma wo Shiranai
- Omamori Himari
- Omiai Aite wa Oshiego, Tsuyokina, Mondaiji.
- Omoi no Kakera
- Omoide no Marnie
- Onara Gorou
- One Off OVA
- One Outs
- One Piece
- One Piece (Dub)
- One Piece 3D2Y
- One Piece 3D2Y (Dub)
- One Piece 3D: Mugiwara Chase
- One Piece Film Z
- One Piece Film: Gold
- One Piece Film: Gold Episode 0 - 711 ver.
- One Piece Luffy – Hand Island no Bouken
- One Piece Movie 10: Strong World
- One Piece Movie 14: Stampede
- One Piece Movie 1: The Great Gold Pirate
- One Piece Movie 2: Clockwork Island Adventure
- One Piece Movie 3: Chopper Kingdom of Strange Animal Island
- One Piece Movie 4: Dead End Adventure
- One Piece Movie 5: The Curse of the Sacred Sword
- One Piece Movie 6: Baron Omatsuri and the Secret Island
- One Piece Movie 7: Karakuri Castle`s Mecha Giant Soldier
- One Piece Movie 8: The Desert Princess and the Pirates
- One Piece Movie 9: Bloom in the Winter, Miracle Sakura
- One Piece Special
- One Piece: Adventure of Nebulandia
- One Piece: Episode of East Blue
- One Piece: Episode of Merry - Mou Hitori no Nakama no Monogatari
- One Piece: Episode of Sabo - 3 Kyoudai no Kizuna Kiseki no Saikai to Uketsugareru Ishi
- One Piece: Episode of Sorajima
- One Piece: Heart of Gold
- One Piece: Nami OVA
- One Punch Man
- One Punch Man (Dub)
- One Punch Man 2nd Season
- One Punch Man 2nd Season (Dub)
- One Punch Man 2nd Season Specials
- One Punch Man Specials
- One Punch Man Specials (Dub)
- One Punch Man: Road to Hero
- One Room
- One Room 2nd Season
- One Room Special
- One Stormy Night Movie
- Onee-chan ga Kita
- Onegai My Melody
- Onegai My Melody: Kuru Kuru Shuffle!
- Onegai Teacher
- Onegai Twins
- Onegai Twins (Dub)
- Onegai Twins EP OVA
- Ongaku Shoujo
- Ongaku Shoujo (TV)
- OniAi
- OniAi Specials
- Onigamiden
- Onigiri
- Onihei
- Onii-chan Dakedo Ai Sae Areba Kankeinai yo ne! Specials
- Onii-chan no Koto Nanka Zenzen Suki Janain Dakara ne!!
- Onikirimaru
- Only Yesterday
- Onmyou Taisenki
- Onsen Yousei Hakone-chan
- Onyankopon
- Ookami Kakushi
- Ookami Kodomo no Ame to Yuki
- Ookami Shoujo to Kuro Ouji
- Ookami Shoujo to Kuro Ouji OVA
- Ookami to Koushinryou II: Ookami to Kohakuiro no Yuuutsu
- Ookami-san to Shichinin no Nakama-tachi
- Ookami-san to Shichinin no Nakama-tachi (Dub)
- Ookamikakushi
- Ookiku Furikabutte
- Ookiku Furikabutte – Big Windup!
- Ookiku Furikabutte –The Summer Tournament Chapter
- Ookiku Furikabutte Season 2
- Ooya-san wa Shishunki!
- Orange
- Orange (Dub)
- Orange: Mirai
- Ore ga Ojousama Gakkou ni \"Shomin Sample\" Toshite Gets♥Sareta Ken
- Ore ga Suki nano wa Imouto dakedo Imouto ja Nai
- Ore Monogatari!!
- Ore no Nounai Sentakushi ga, Gakuen Love Comedy wo Zenryoku de Jama Shiteiru OVA
- Ore wo Suki nano wa Omae dake ka yo
- Ore, Twintail ni Narimasu. (Dub)
- Ore, Twintails ni Narimasu.
- Ore-sama Kingdom
- Ore-tachi ni Tsubasa wa Nai
- Oreca Battle
- Oregairu
- Oregairu OVA
- Oreimo
- OreImo 2
- Orenchi no Furo Jijou
- OreShura
- Origin: Spirits of the Past
- Oruchuban Ebichu
- Osake wa Fuufu ni Natte kara
- Osamu Tezuka`s Buddha Movie 1
- Oseam
- Oshi ga Budoukan Ittekuretara Shinu
- Oshiete Mahou no Pendulum: Rilu Rilu Fairilu
