| Act | Discs | Tracks |
| O'Jays, The | 0 | 1 |
| Oasis | 7 | 35 |
| Ocean Colour Scene | 0 | 1 |
| Ocie Stockard & his Wanderers | 0 | 1 |
| Octopus | 0 | 1 |
| Odyssey | 0 | 4 |
| Ofra Haza | 1 | 9 |
| Ohio Express | 0 | 1 |
| Oleta Adams | 0 | 4 |
| Olive | 2 | 12 |
| Olivia Newton John & ELO | 0 | 1 |
| OMD | 0 | 1 |
| Omer Simeon | 0 | 1 |
| Orange Juice | 0 | 2 |
| Orb, The | 0 | 1 |
| Orchestra & Chorus conducted by Morris Stoloff | 0 | 6 |
| Orchestra & Chorus conducted by Nelson Riddle | 0 | 3 |
| Orchestra & Chorus of la Scala, Milan | 2 | 28 |
| Orchestra & Chorus of Paris Opera-Comique | 0 | 5 |
| Orchestra & Chorus of the Capitole, Toulouse | 1 | 13 |
| Orchestra & Chorus of the Opera House, Rome | 4 | 55 |
| Orchestra & Chorus of the Paris Opera | 0 | 8 |
| Orchestra & Chorus of the Teatro dell'Opera di Roma | 0 | 16 |
| Orchestra & Chorus of the Theatre National de l'Opera | 2 | 18 |
| Orchestra de la Societe des Concerts du Conservatoire | 1 | 6 |
| Orchestra Sinfonica di Milano della Radiotelevisione Italiana | 3 | 16 |
| Orchestral Manoevres in the Dark | 0 | 1 |
| Orchestre National de la Radiodiffusion Francaise | 1 | 11 |
| ORF Symphony Orchestra | 0 | 1 |
| Origin, The | 1 | 11 |
| Original Dixieland Jazz Band | 0 | 2 |
| Original New Orleans Rhythm Kings | 0 | 1 |
| Original Tuxedo Jazz Orchestra | 0 | 1 |
| Originals, The | 0 | 1 |
| Oscar Alemàn | 0 | 1 |
| Oscar Peterson | 0 | 1 |
| Oscar Peterson Trio, The | 0 | 1 |
| Oscar Pettiford and his Eighteen All Stars | 0 | 4 |
| Osibisa | 0 | 3 |
| Otis Redding | 1 | 19 |
| Otis Redding & Carla Thomas | 1 | 12 |
| Ottawan | 0 | 2 |
| Outhere Brothers, The | 2 | 13 |
| Oyster Band, The | 0 | 6 |
My Music Collection was last updated: 16 April 2000