- U.E.M 9
- UBX Master 3
- UBerserker 3
- UEM 14
- UEd2 2
- UFO 2
- UGL 2
- UK-Scorpion 2
- UKBikenut) 3
- ULT Basement 2
- UNKNOWN! 3
- UNREALLOCO 7
- UN||XpanD 7
- UT 3
- UT 2K4) 2
- UT2004 2
- UT99-Fusion | UT2004-Flak 2
- UTCP Maddmapper: Dave {Maddog} Mortensen 3
- UTGhost 4
- UTPG 4
- UbH-IceIst aka UbH 4
- Uber {Hunglo} 3
- ÜberByte 2
- Ulo 2
- UltraSonic 3
- Ultron! 9
- Ulysses_30 4
- Un1ucky 3
- UnFuKWiTAbLE 10
- UnLeaded 31
- UnPfhorgiven 4
- UnShame 7
- UnbeKabal 2
- UncleD 2
- Uncle_Bob 40
- Uncledumpy 26
- Uncledumpy - "Coyote" (original) 5
- Uncommon 24
- UnconnecteD 2
- Underscore 5
- Undertaker 7
- UndrSiege 2
- UnholyCreator 2
- Union 8
- United Scriptors 2
- United Scriptors : »SZO«Zeß 2
- UnitedSniperMappers 2
- Unreal 19
- Unreal Killers 2
- Unreal4Eva 3
- UnrealGGecko 9
- Unseen[WOLFIN] 4
- Unseen[WOLFIN]-NewED[void]XeMz 2
- Untitled 2
- Uri19 4
- UsAaR33 7
- Usama 4
- Useless 4
- Uwe "Rockhound" Goetz 2
- Uwe 'Fierce' Herrmann 3