| Oak | Welcome to our fair | Topic | 12TS212 | |
| Ofarim Esther & Abi | Neue Songs der Welt | Ex Libris | SG 6701 | |
| Oldfield Mike | Tubular bells | Virgin | 87 541 IT | |
| Oldfield Mike | Incantations | Virgin | 2 676 716 | |
| Oldfield Mike | Boxed | Virgin | VBOX 1 | |
| Oldfield Mike | Ommadawn | Virgin | 89552 XOT | |
| Oldfield Mike | Hergest Ridge | Virgin | 88134 IT | |
| Oldfield Mike | Tubular bells | Virgin | 87541 IT | |
| Oldfield Mike | The orchestral tubular bells | Virgin | V 2026 | |
| Olsson Kai | Crazy love | Chrysalis | 6 307 656 | |
| Olsson Nigel | Nigel Olsson | Rocket | ROLL 2 | |
| Olympic Rock & Blues Circus | Olympic rock & blues circus | Jeton | 1003321 | |
| Omega | Omega III | Bacillus | BAC 2030 | |
| One | Come | Grunt | FTR 1008 | |
| Orange blossom | Keep on pushing | Westwood | WRS 038 | |
| Orbison Roy | Mystery girl | Virgin | V 2576 | |
| Oregon | Roots in the sky | Elektra | ELK 52 169 | |
| Oregon | Oregon | ECM | 1258 | |
| Original Animals | Before we were so rudely interrupted | Barn | 2 365 106 | |
| Original Broadway Cast | Hair | RCA Victor | lso-1150 | |
| Os Ritimistas Brasileiros | Stereophonic journey in percussion | Marble Arch | MALS 1361 | |
| Oskar Lee | Lee Oskar | Far Out | 900 503 | |
| O'Sullivan Gilbert | A Stranger in my Own Back Yard | MAM | MAM SS 506 | |