| On a Roll (2017) | 3,562,195 | 374 |
| On A Roll 3D (2015) | 2,802 | 21 |
| On a Summer Night (2025) | 0 | 1 |
| On Air (2021) | 110,824,348 | 3,267 |
| On Dark Terms (2023) | 98,404 | 52 |
| On My Own (2016) | 184,145,459 | 1,677 |
| On my own: A Hot Isekai Adventure (2023) | 0 | 0 |
| On Point (2024) | 9,664,690 | 704 |
| On Reflection (2007) | 117,987 | 10 |
| On Rusty Trails (2016) | 66,504 | 74 |
| On the Ball (1993) | 6,684,411 | 497 |
| On the Dragon Wings - Birth of a Hero (2022) | 1,042 | 6 |
| On the Hunt (2024) | 842,867 | 405 |
| On The Job (2023) | 3,559,981 | 324 |
| On the Peril of Parrots (2023) | 570 | 5 |
| On The Road: Truck Simulator (2017) | 6,884,326 | 2,684 |
| On the Run: Rogue Heroes (2024) | 752 | 1 |
| On Your Hands (2022) | 241,867 | 34 |
| On Your Tail (2024) | 1,220,594 | 259 |
| On-Court Tennis (1984) | 14,639 | 14 |
| Once a Porn a Time 2 (2024) | 0 | 0 |
| Once a Tale (2024) | 12,073 | 56 |
| Once Again (2022) | 31,182,840 | 2,674 |
| Once Bitten, Twice Dead! (2015) | 162,390 | 32 |
| Once Human (2024) | 104,729,131 | 36,766 |
| Once on a windswept night (2017) | 1,453 | 34 |
| Once upon a Dungeon - Infinity (2025) | 3,502 | 17 |
| Once upon a Dungeon II (2023) | 944 | 10 |
| Once Upon a Jester (2022) | 268,207 | 274 |
| Once Upon A Puppet (2025) | 248,822 | 258 |
| Once Upon a Rogue's Tale (2024) | 34,236 | 33 |
| Once Upon A Siege (2022) | 0 | 0 |
| Once Upon a Time in the Colony (2021) | 0 | 0 |
| Once Upon A Time: Abracadabra (1991) | 446 | 7 |
| Once Upon A Time: Little Red Riding Hood (1991) | 1,700 | 4 |
| Once Upon an All Hallow's Eve (2017) | 394 | 9 |
| Onde (2022) | 9,247,546 | 994 |
| One (1997) | 5,645,463 | 576 |
| One (2005) | 29,881 | 24 |
| One Bear Army (2024) | 42 | 2 |
| One Boss One Fight (2024) | 29,194 | 30 |
| ONE BTN BOSSES (2024) | 21,654 | 52 |
| One Bullet left (2018) | 156,057 | 21 |
| One Chance (2010) | 47,775,711 | 511 |
| One Clone Left (2016) | 0 | 0 |
| One Day in London (2016) | 73,703 | 169 |
| One Deck Dungeon (2018) | 742,855 | 455 |
| One Dog Story (2017) | 55,793 | 211 |
| One Dreamer (2020) | 35,328 | 113 |
| One Dreamer (2022) | 82,615 | 97 |
| One Drunken Knight (2022) | 426 | 12 |
| One Eleven (2023) | 558,685 | 471 |
| One Epic Game (2011) | 268,251 | 53 |
| One Escape (2021) | 12,670,209 | 573 |
| One Eyed Kutkh (2017) | 59,198 | 114 |
| One Finger Death Punch (2013) | 24,961,210 | 3,323 |
| One Finger Death Punch 2 (2019) | 2,813,340 | 2,026 |
| One Hand Clapping (2020) | 66,716,322 | 3,778 |
| One Hit KO (2017) | 219,125 | 44 |
| One Hour And A Straight Line (2024) | 0 | 0 |
| One Hour One Life (2018) | 94,950,093 | 3,321 |
| One Hundred Ways (2015) | 104,589 | 47 |
| One Last Chance (2016) | 983,841 | 105 |
| One Last Day (2015) | 22,764 | 18 |
| One Last Time (2022) | 43,520,730 | 1,601 |
| One Late Night: Deadline (2014) | 5,915,075 | 208 |
| One Lonely Outpost (2022) | 1,224,366 | 847 |
| One Long Night with the Circleheads (2024) | 13 | 1 |
| One Man and His Droid (1985) | 28,083 | 38 |
| One Man Army (2011) | 6,085,102 | 871 |
| One Manga Day (2015) | 409,714 | 80 |
| One Many Nobody (2022) | 658 | 18 |
| One Military Camp (2023) | 9,253,485 | 1,742 |
| One Million People's Nobunaga's Ambition (2010) | 16,166 | 4 |
| One Million Worlds (2019) | 16 | 1 |
