- 3 "Ok-Billy"
- 3 'opiumunknown'
- 4 Oak
- 3 Ob1-Kenobi
- 3 Obi-Wan
- 2 oblivion100
- 12 Octavian "VikingWasDead" Ornoch
- 2 Octopussy
- 3 OddMods Team
- 13 Odedge
- 3 Odhinn Kohout
- 2 Odin "Bareodin"
- 2 ODM
- 2 Odysseus
- 4 OFG
- 2 Ogr81
- 2 Ogr81<DVP>
- 3 Oki "Maverick" Blatnik
- 3 Oki "MAVERICK" Blatnik and "King Henri"
- 7 Ola 'Jolle' Frid
- 2 Ola and Emil Frid
- 9 Olav "" Gjerde
- 3 Olav 'Tonito' Ã…sheim
- 2 Olav Gjerde Port LaTeRaLuS
- 2 Olav Groenaas Gjerde
- 11 Old Geezer
- 5 old_man_funk
- 3 OldeDevil
- 2 Olethros
- 10 Oli "Olister" Wood
- 4 Olindo -=BlueSilver=- Bottura
- 3 Oliver 'PlagueLord' Gerestein
- 2 Oliver 'Raziel31' Garrigue-]|YO!|[
- 2 Oliver 'WinRAZ' Garrigue
- 2 Oliver Jones
- 2 Oliver'Raz'G.
- 2 Olivier "NEURO" Chapuis
- 3 OLIVIER KOOS
- 2 OmegaDelta
- 4 OmletteDuFromage
- 4 On@g@
- 2 Ondrej Vojta in 2003
- 2 One_Man_Clan
- 2 ONS-Recon
- 2 oo6 (-Roel`)
- 5 OpNox
- 3 OpticalShadows
- 5 orbitx
- 3 orc00 (modified from jetskimod)
- 4 Ordzo
- 2 Organized Evolution
- 2 Original [FED]Billy_B, Remake SK
- 2 Original BONE, redone theswarm
- 6 Original Concept Rare(c), Modified Mr. Bond
- 2 Original Eric Ettes, Edited brett`
- 2 Original Morbias Myscha the sled dog. Modified into the Tower Francois Lacombe, aka Orion(Co30)
- 2 Original Myscha, Sieged SK
- 2 original Unreal map, edited Strider Hiryu