| Name | Roles |
|---|---|
| Orton, Erik | Music, Lyrics, Book |
| Ortoneda, Alexandra | Performer |
| Ortu, Marco | Performer |
| Ortwein, Terrence | Conductor |
| Orty, Sandrine | Performer |
| Orvalho, Robert | Performer |
| Orwander, Henrik | Performer |
| Orye, Bart | Orchestrations (2), Conductor, Music_Director, Vocal_Arrangements (2), Producer (2) |
| Oryema, Geoffrey | Performer |
| Os, Arco van | Lyrics |
| Os, Gina van | Performer |
| Os, Hans van | Performer (2) |
| Os, Martin van | Performer |
| Osa, Sam | Music |
| Osadzinski, Stef | Orchestrations |
| Osato, Sono | Performer (2) |
| Osbahr, Carmen | Performer (3) |
| Osbaldeston, Jon | Performer |
| Osborn, Jason | Music_Director, Vocal_Arrangements |
| Osborn, Kelsi | Performer |
| Osborn, Leonard | Performer (9) |
| Osborn, Paul | Book |
| Osborn, Susan | Performer |
| Osborne, Ben | Performer |
| Osborne, Bobby | Liner_Notes |
| Osborne, David | Orchestrations, Producer, Performer |
| Osborne, Emily | Performer |
| Osborne, Frances | Performer |
| Osborne, Gary | Lyrics (2), Performer |
| Osborne, Georga | Performer (2) |
| Osborne, Georgia | Performer |
| Osborne, Jeffrey | Performer |
| Osborne, Joe | Orchestrations |
| Osborne, John | Liner_Notes |
| Osborne, Kevin | Vocal_Arrangements, Performer (4) |
| Osborne, Neil | Conductor, Performer |
| Osborne, Robert | Performer (5) |
| Osborne, Stephen | Performer |
| Osborne, Steven | Performer |
| Osborne, Tony | Orchestrations, Conductor (11), Music_Director (2) |
| Osborne, Will | Lyrics, Book, Performer |
| Osbourn, Leonard | Performer |
| Osbourne, Elizabeth | Performer |
| Osbourne, Georgia | Performer |
| Osbourne, Tony | Conductor |
| Oscar, Brad | Performer (16) |
| Oscar, Wild | Producer |
| Oschwald, Markus | Performer (2) |
| Oseland, Laura | Performer |
| Osentoski, Whitney | Performer |