- Oniichan no Koto nanka Zenzen Suki ja Nai n da kara ne!! Special
- Oniichan wa Oshimai!
- Oniichan wa Oshimai! (Uncensored)
- Oniisama e...
- Onikirimaru
- Onimomomomo
- Onimusha
- Onipan!
- Onkyo Seimeitai Noiseman
- Onmyou Kaiten Re:Birth
- Onmyou Taisenki
- Onmyouji
- Onsen Yousei Hakone-chan
- Onyankopon
- Ooi! Tonbo
- Ooi! Tonbo 2nd Season
- Ookami Kodomo no Ame to Yuki
- Ookami Shoujo to Kuro Ouji
- Ookami to Koushinryou
- Ookami to Koushinryou II
- Ookami to Koushinryou II: Holo no Short Anime
- Ookami to Koushinryou II: Ookami to Kohakuiro no Yuuutsu
- Ookami to Koushinryou: Merchant Meets the Wise Wolf
- Ookami-san to Shichinin no Nakama-tachi
- Ookii 1 Nensei to Chiisana 2 Nensei
- Ookiku Furikabutte
- Ookiku Furikabutte: Kihon no Kihon
- Ookiku Furikabutte: Natsu no Taikai-hen
- Ookiku Furikabutte: Natsu no Taikai-hen – Mokuhyou
- Ookuninushi to Sukunabikona
- Oomuro-ke
- Oomuro-ke: Dear Friends
- Oooku
- Ooyasan wa Shishunki!
- Ooyukiumi no Kaina
- Ooyukiumi no Kaina: Hoshi no Kenja
- Opus.COLORs
- Orange
- Orange: Mirai
- Ore dake Haireru Kakushi Dungeon
- Ore dake Level Up na Ken
- Ore dake Level Up na Ken Season 2: Arise from the Shadow
- Ore dake Level Up na Ken: ReAwakening
- Ore dake Level Up na Ken: Specials
- Ore ga Ojousama Gakkou ni "Shomin Sample" Toshite Gets♥Sareta Ken
- Ore ga Ojousama Gakkou ni "Shomin Sample" Toshite Gets♥Sareta Ken Specials
- Ore ga Suki nano wa Imouto dakedo Imouto ja Nai
- Ore ga Suki nano wa Imouto dakedo Imouto ja Nai Specials
- Ore Monogatari!!
- Ore no Imouto ga Konnani Kawaii Wake ga Nai
- Ore no Imouto ga Konnani Kawaii Wake ga Nai Specials
- Ore no Imouto ga Konnani Kawaii Wake ga Nai.
- Ore no Imouto ga Konnani Kawaii Wake ga Nai. Specials
- Ore no Kanojo to Osananajimi ga Shuraba Sugiru
- Ore no Nounai Sentakushi ga, Gakuen Love Comedy wo Zenryoku de Jama Shiteiru
- Ore no Nounai Sentakushi ga, Gakuen Love Comedy wo Zenryoku de Jama Shiteiru OVA
- Ore no Sora Keiji-hen
- Ore wa Seikan Kokka no Akutoku Ryoushu!
- Ore wa Subete wo "Parry" suru: Gyaku Kanchigai no Sekai Saikyou wa Boukensha ni Naritai
- Ore wo Suki nano wa Omae dake ka yo
- Ore wo Suki nano wa Omae dake ka yo: Oretachi no Game Set
- Ore, Tsushima
- Ore, Tsushima (ONA)
- Ore, Twintail ni Narimasu.
- Oreca Battle
- Orenchi no Furo Jijou
- ORESUKI Are you the only one who loves me: Game Over
- Oretachi ni Tsubasa wa Nai: Under the Innocent Sky.
- Orient
- Orient: Awajishima Gekitou-hen
- Oroka na Tenshi wa Akuma to Odoru
- Osakana wa Ami no Naka
- Osake wa Fuufu ni Natte kara
- Osake wa Fuufu ni Natte kara: Yuzu Atsukan
- Osananajimi ga Zettai ni Makenai Love Comedy
- Oshi ga Budoukan Ittekuretara Shinu
- Oshi no Ko 2nd Season
- Oshi no Ko Specials
- Oshiete Mahou no Pendulum: Rilu Rilu Fairilu
- Oshiete! Galko-chan
- Oshiete! Galko-chan: Natsuyasumitte Hontou Desu ka?
- Osomatsu-kun (1988)
- Osomatsu-san
- Osomatsu-san 2nd Season
- Osomatsu-san 3rd Season
- Osomatsu-san 4th Season
- Osomatsu-san Movie
- Osu!! Karate-bu
- Otaku no Seiza
- Otaku no Video
- Otenki Oneesan
- Otogi Juushi Akazukin
- Otogi Story Tenshi no Shippo
- Otogi Story Tenshi no Shippo Specials
- Otogizoushi
- Otohime Connection
- Otome Game no Hametsu Flag shika Nai Akuyaku Reijou ni Tensei shiteshimatta...
- Otome Game no Hametsu Flag shika Nai Akuyaku Reijou ni Tensei shiteshimatta… Movie
- Otome Game no Hametsu Flag shika Nai Akuyaku Reijou ni Tensei shiteshimatta... OVA
- Otome Game no Hametsu Flag shika Nai Akuyaku Reijou ni Tensei shiteshimatta... X
- Otome Game Sekai wa Mob ni Kibishii Sekai desu
- Otome Youkai Zakuro
- Otome Youkai Zakuro Picture Drama
- Otona no Bouguya-san
- Otona no Bouguya-san II
- Otonari ni Ginga
- Otonari no Tenshi-sama ni Itsunomanika Dame Ningen ni Sareteita Ken
- Ou Dorobou Jing
- Ougon Senshi Gold Lightan
- Ougon Yuusha Goldran
- Ouran Koukou Host Club
- Ouritsu Uchuugun: Honneamise no Tsubasa
- Ousama Game The Animation
- Ousama Ranking
- Ousama Ranking: Yuuki no Takarabako
- Oushitsu Kyoushi Heine
- Oushitsu Kyoushi Heine Movie
- Outbreak Company
- Outlanders
- Oval x Over
- Over Drive
- Overflow
- Overflow (Uncensored)
- Overlord
- Overlord II
- Overlord III
- Overlord IV
- Overlord Movie 1: Fushisha no Ou
- Overlord Movie 2: Shikkoku no Eiyuu
- Overlord Movie 3: Sei Oukoku-hen
- Overlord: Ple Ple Pleiades
- Overlord: Ple Ple Pleiades - Clementine Toubou-hen
- Overlord: Ple Ple Pleiades 2
- Overlord: Ple Ple Pleiades 3
- Overlord: Ple Ple Pleiades 4
- Overman King Gainer
