- Ottaviani, Giuseppe feat. Hurley, Shannon
- Ottaviani, Giuseppe feat. Linnea Schössow
- Ottaviani, Giuseppe feat. Lo-Fi Sugar
- Ottaviani, Giuseppe feat. McTeague, Tricia
- Ottaviani, Giuseppe feat. Mecorio, Francesco
- Ottaviani, Giuseppe feat. Mecorio, Francesco
- Ottaviani, Giuseppe feat. Pickup, Stephen
- Ottaviani, Giuseppe feat. Rene, Jennifer
- Ottaviani, Giuseppe feat. Seri
- Ottaviani, Giuseppe feat. Shepherd, Amba
- Ottaviani, Giuseppe feat. Vitamin B
- Ottaviani, Giuseppe feat. Yates, Clara
- Ottaviani, Giuseppe with Lumiere, Eric
- Ottavo Padiglione
- Ottawa (Indie Band)
- Ottawan
- Ottawans
- Otten, Mark
- Otten, Paul (singer/songwriter)
- Otten, Thomas (French countertenor)
- Otter, Anne Sofie von (mezzo-soprano)
- Otter, Anne Sofie von & Costello, Elvis
- Otter, Anne Sofie von, Musiciens du Louvre, Les, Minkowski, Marc
- Otter, Till
- Ottesen, Janove
- Ottewell, Ben
- Ottman, John
- Otto (Brazilian singer)
- Otto (UK singer-songwriter Christian Punter)
- OTTO (Otto Benson)
- Otto Dix
- Otto feat. Gilberto, Bebel
- Otto Knows
- Otto Knows feat. Avicii
- Otto Normal
- Otto Ohm
- Otto, James
- Otto, James feat. Milsap, Ronnie
- Otto, Natalino
- Ottobrenero (Italian progressive metal)
- Ottolini, Mauro
- Ottolini, Mauro e la sua Orchestra Ottovolante
- Ottolini, Mauro, Sousaphonix
- Ottolini, Robyn
- Ottoman (Icelandic blues rock band)
- OttoMattic
- Ottone pesante (Italian band)
- Ottum, Josh
- Otu (Finnish audio engineer & musician, Moonic Productions)
- Otway, John
- Otway, John & Barrett, Wild Willy
- Otway, John & Barrett, Wild Willy
- Otyg
- Otzeki
- Ötzi (Oakland post-punk)
- Ötzi, DJ (Austrian entertainer and schlager singer)
- Ötzi, DJ & Bellamy Brothers, The
- Ötzi, DJ & Gott, Karel
- Ötzi, DJ & Hall, Kate
- Ötzi, DJ & P., Nik
- Ötzi, DJ & P., Nik
- Où est le Swimming Pool (English synthpop group)
- Ou2s (french rapper)
- Ouai Stéphane
- Oub LCK
- OUBEL
- Oubéret
- Oubliette (melodic black metal band from Tennessee)
- Ouboter, Maaike
- Oud west
- Ouellet, Karim
- Ouellet, Karim feat. Sarahmée
- Ouellet, Yvan
- Ougenweide
- Ought
- Oui 3
- Oui lele
- Ouija Macc
- Ouijabeard (Rock, Hardrock, Metall)
- Ouimette, Steve
- Oulton, Quinn
- Oum (Oum el Ghaït Benessahraoui)
- Oum Shatt
- Oumar (French rapper Oumar Magassa)
- Oumou Dioubate
- Oumua
- Ounsworth, Alec
- Our 11th Hour (Progressive Rock Group from Syracuse, NY)
- Our Broken Garden
- Our Brother the Native
