- Oel & Polygon -- of these hope
- Of Truth & Stories -- Off Lymits
- Off on a Tangent -- Office of Future Plans
- Office-(r)6 -- OfflagaDiscoPax
- Offlicence -- O.F.T.B.
- Oftb -- O.G. Swiffff
- OG Whoryde -- Oguinye
- Ogun -- oh no fiasco
- Oh No Joe -- Ohayo
- OHCA -- Ohmega Tribe
- Ohmega Watts -- Oicho
- Oidominion...What? -- O.J. Newcomb
- O.J. Simpson -- Ojars Grinsbergs