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- The O'Jays
- Oasis (North America/Japan)
- October Project
- Off-Shore
- Olly Murs (The X Factor UK contestant)
- Oh Land
- Omarion
- The Only Ones
- Open Air Stereo
- Ozzy Osbourne
- Kelly Osbourne
- Olinee
- Outkast
Read more about this topic: List Of Epic Records Artists