Marvel
| Name | Super Name | Code | Actions |
|---|---|---|---|
| Ogun | Ogun | Ogun | Show |
| Old Lace | Old Lace | Old-La… | Show |
| Olivier | Olivier | Olivier | Show |
| Omega | Omega | Omega | Show |
| Omega Clan | Omega Clan | Omega-… | Show |
| Omega Red | Omega Red | Omega-… | Show |
| Omega the Unknown | Omega the Unknown | Omega-… | Show |
| Onslaught | Onslaught | Onslau… | Show |
| Onyxx | Onyxx | Onyxx | Show |
| Oracle | Oracle | Oracle | Show |
| Orator | Orator | Orator | Show |
| Orb | Orb | Orb | Show |
| Ord | Ord | Ord | Show |
| Orka | Orka | Orka | Show |
| Orphan-Maker | Orphan-Maker | Orphan… | Show |
| Otomo | Otomo | Otomo | Show |
| Outlaw | Outlaw | Outlaw | Show |
| Outlaw Kid | Outlaw Kid | Outlaw… | Show |
| Overdrive | Overdrive | Overdr… | Show |
| Overmind | Overmind | Overmi… | Show |