| Title | Publisher | Year | Language | Documents |
|---|---|---|---|---|
| Octavo Pasajero, El | Jarel |
2001 | Spanish | |
| Ogre | Richard Hunt | ? | English | |
| Okigoli | Jarel |
2000 | Spanish | |
| Oklib's Revenge | Syntax Adventure Magazine | 1992 | English | |
| On the Other Side | Antonio Márquez Marín |
2000 | English | |
| On the River Styx | H. W. Williams | ? | English | |
| One Smurfy Day | Paul Allen Panks |
? | English | |
| Oo-topos | Penguin Software |
1981 | English | Solution |
| Oostwest 3 | Cobrasoft | 2010 | Dutch | |
| Ooze: Creepy Nites | Dragonware | 1989 | English | Solution |
| Operacion : Operacion | Krac | 2000 | Spanish | |
| Orfeo y Euridice | 3PSOFT | 1991 | Spanish | |
| Original Adventure, The | Norell Data Systems |
1982 | English | Solution, Map |
| Orphee - Voyage Aux Enfers | Loriciels | 1985 | French | Solution |
| Ouija | Mago soft | 1996 | Spanish |