- One Putt Golf
- One Shot Blade
- One Shot Runner
- One Tap Ninja
- One-Two-Stack !!
- One Man - Reflex Brawler
- OnePunch -The New Hero-
- OneShot: Sniper Assassin
- Onet Connect 2016 - Link Link
- Onet Craft
- Onet Fruit Unlimited
- Onet Online
- ONIGOKKO
- Only One
- Onmyoji Arena
- OOOO by Lemon Jam
- Oops! Zombies
- Oops!! Knife
- Oopstacles
- Open Case Simulator
- Open World Madout Mafia City
- Operation: ATAK
- Operation: ANKA
- OPERATION DRACULA
- Operation Dracula X
- Operation Sky
- Operation Smoochy
- Operation wow HD
- Operation: New Earth
- Ophidia
- Oportuno Beyond Infinity Pills Game HD
- Orange Bouncing Ball
- Orange Juice Brick Breaker
- Orange.
- Orb Defense AR
- Orb Wars
- Orbia
- ORBIT - multiplayer space battles!
- ORBIT AR
- Orbit Buster
- Orbit defenders
- Orbit Jumper
- Orbit Riders
- Orbit Strike
- Orbital Invaders. Space action
- Orbital Invaders: Retro game
- Orbital Rockets
- Orbitz Planet Simulator
- Orbo's Escape
- Orbt XL
- Orc Warrior Army Siege 3D - Royal Navy dead air counter battle
- ORC: Vengeance - GameClub
- Ordia
- Origami.io