| Name | Steam ID | Records | WRs |
|---|---|---|---|
| OppoiJaegr | 76561198182572531 | 8 | 0 |
| opp ƪµɱµkἀηᶑα | 76561198212355911 | 1 | 0 |
| OPRAH | 76561198216472764 | 2 | 0 |
| opt1cx | 76561198070081273 | 3 | 0 |
| oPti | 76561197989065442 | 4 | 0 |
| Opticalx | 76561199227344506 | 28 | 0 |
| Optigrill | 76561198051844735 | 4 | 0 |
| Optixx | 76561197984554346 | 1 | 0 |
| optkz | 76561197985276193 | 3 | 0 |
| Optrix | 76561198147972397 | 1 | 0 |
| Optиmиsт | 76561198387544892 | 19 | 0 |
| oQn | 76561198051734742 | 12 | 0 |
| o.Qv | 76561197967621265 | 3 | 0 |
| or2xb | 76561198037546906 | 7 | 0 |
| Oraltrolly | 76561198910602197 | 2 | 0 |
| Orange | 76561198138860062 | 1 | 0 |
| Orange | 76561198033387804 | 405 | 0 |
| OrangeCupcake | 76561197993022392 | 2 | 0 |
| Orange Julius | 76561197961892331 | 1 | 0 |
| orangepylon | 76561197998831768 | 1 | 0 |
| Oranger | 76561197983857550 | 1 | 0 |
| orangutan | 76561198097419969 | 1 | 0 |
| Orb | 76561198081924604 | 19 | 0 |
| Orbb | 76561197994217062 | 1 | 0 |
| Orbb | 76561198124792107 | 1 | 0 |
| ♛ Orb In Space ♛ | 76561197976413454 | 1 | 0 |
| Orbital | 76561198942291152 | 1 | 0 |
| OrbitalBoomStick | 76561198159571154 | 3 | 0 |
| OrbitaLᵂᴬᴿᴾ | 76561198009631429 | 3 | 0 |
| orca | 76561198195866023 | 97 | 1 |
| Orchidaceae | 76561198052485066 | 1 | 0 |
| Orchidoclaste | 76561198147331176 | 1 | 0 |
| OrcHound | 76561197990330395 | 2 | 0 |
| Orciva | 76561197978738919 | 2 | 0 |
| ordeille⚸ ♘ | 76561197985689288 | 20 | 0 |
| Order 66 | 76561198159594363 | 1 | 0 |
| OrDox | 76561197974204454 | 1 | 0 |
| Oreki | 76561198085182053 | 1 | 0 |
| Oreo! | 76561197973015103 | 2 | 0 |
| orf | 76561197961215772 | 1 | 0 |
| örfstilflet | 76561198089406957 | 1 | 0 |
| organic ²·º | 76561198037773830 | 9 | 0 |
| ori0n | 76561198799873638 | 4 | 0 |
| oriano | 76561198099916327 | 2 | 0 |
| Origin | 76561198966814346 | 62 | 0 |
| orInge | 76561198065325826 | 1 | 0 |
| orion | 76561198120301921 | 21 | 0 |
| Orion | 76561198262276972 | 1 | 0 |
| Orion | 76561198013059692 | 14 | 0 |
| Orion | 76561198007355142 | 1 | 0 |