- Ore Blast Mania
- Organic Pop
- Orgo Tutor: Chemistry Isomers
- Oriel Llythrennau Unigol
- Origame
- Origami - Origami Art
- Origami Challenge
- Origami Math
- Origami Paper Art game no WiFi
- Origamist
- Original Hangman
- Original Mahjong™
- Orion - A Journey Beyond
- Orixo
- Ormnyr
- Ornament Buster
- Osaka Map Puzzle
- Osmo Coding Awbie
- Osmo Coding Duo
- Osmo Counting Town
- Osmo Math Wizard
- Osmo Newton
- Osmo Numbers
- Osmo Numbers Cooking Chaos
- Osmo Numbers Cooking Chaos
- Osmo Numbers Toybox
- Osmo Shape Builder
- Osmo Tangram
- Osmo Tangram Classic
- Osmo Words Chomp
- Osmo Words Explorers
- Osmos
- Osmos for iPad
- Osmosmerka: Solve Word Search Puzzles Using Serbian Latin and Cyrillic Alphabets
- Osushiya-san
- OsXs
- OT Country Quiz
- Othello Multiplayer
- Othelloda Ext
- Other
- Fairy Tales : Hidden Objects
- Our Last Journey
- Our Treasure Hunt
- Our Ways
- Ouro
- Ouroboros: Infinity puzzle
- Out of Ink - Drawing Game
- Outage - A Memory Puzzle Game
- Outbreak ES
- Outbreak Unlimited
- Outer Space Miracle Alien - Gogo Stack It Up Skyward Stacker
- Outfolded
- Outlaw HQ for RDR2
- Outside World
- Outsider
- Outsider: After Life
- Ouvrir une photo
- Over the rain
- Overclock the Game
- Overhang
- Overlap: Spatial Reasoning
- Overlink
- Overpaint
- Overtake All
- OverTen
- Owl Jigsaw Puzzle Learning
- Space OXO
- OXO - TicTacToe
- OX益智棋
- Oyaji Hair