O
- Gilbert Obermair ~ Push
- Sean O'Connor ~ Slay
- Marc Odier ~ Trioker
- Edward Okamura ~ Pipeline
- Eugene Oker ~ Dual (with Rudolf Ross)
- Anssi Ollikainen ~ Trimok (with J. Ollikainen and T. Saarinen)
- Jukka Ollikainen ~ Trimok (with A. Ollikainen and T. Saarinen)
- Philip Orbanes ~ Realm
- Greg Otero ~ Roundabout
