- Oreca Battle
- Osamake: Romcom Where The Childhood Friend Won't Lose!
- Over the Sky
- Otome Game no Hametsu Flag shika Nai Akuyaku Reijou ni Tensei shiteshimatta... OVA
- Otome Youkai Zakuro Picture Drama
- Ozmafia!!
- Oblivion Island: Haruka and the Magic Mirror
- Overlord
- Overlord: Ple Ple Pleiades 2
- Overlord: Ple Ple Pleiades - Clementine Toubou-hen
- Ozma
- One Step Toward Freedom
- One-Million Year Trip: Bander Book
- Operation Han-Gyaku-Sei Million Arthur
- Oshi No Ko Season 2
- Otaku Elf
- Obsolete
- Oda Cinnamon Nobunaga
- Obey Me!
- Oam Monogatari: Sono Natsu, Watashi ga Shitta koto
- Obey Me! 2nd Season
- Occultic;Nine
- Ochibi-san
- Ocha-ken: Hotto Monogatari
