U6
- 1962 United States Tri-Service aircraft designation system
- 6U (disambiguation)
- American Power Boat Association
- Berlin U-Bahn
- British NVC community U6
- Frankfurt U-Bahn
- German submarine U-6
- Haplogroup U6
- Miss Madison
- Munich U-Bahn
- Rapid transit
- U6 (Berlin U-Bahn)
- U6 (Vienna U-Bahn)
- U6 spliceosomal RNA
- Ultima VI
- Unemployment
- Upper sixth
- Ural Airlines
- Vienna U-Bahn