- Ubaghuns Tëhe by Mardikhouran (102 features)
- Ueyoonja by penguinsquishy (7 features)
- UFOSAT by Fau Sa (0 features)
- Uirian by Uiri (118 features)
- Ukhshaya by Udrihel (39 features)
- Ukumusi by decadentmuffin (26 features)
- Ulmiric by Dúrfin (24 features)
- Undercommon by Enrique Gamez (81 features)
- ungxau by Tapeworm (0 features)
- Unish by Sejong University (90 features)
- Universal by G.I. Muravkin & L.I.Vasilevskij (9 features)
- Universalglot by Jean Pirro (100 features)
- UNLWS by Sai, Alex Fink (1 feature)
- urdcax by Blob doom/thegranddestroyer (67 features)
- Uropi by Joël Landais (139 features)
- Urracheg by WhimsicalXellos (15 features)
- Usangtari by Brv (106 features)
- Uscaniv by Kári Emil Helgason (138 features)
- Ussaria by Solarius (128 features)
- Uyendur by clawgrip (13 features)
- Uzīdņv by Eddie (0 features)
- Uzkian by aarginost (140 features)