U6

U6 or U-6 may refer to:

* German submarine "U-6", one of several German submarines
* U-6, a railway line on several German underground railway systems:
**U6 U-Bahn line, a line on the Berlin U-Bahn
**U-6, a line on the Frankfurt U-Bahn
**U-6, a line on the Munich U-Bahn
**U-6, a line on the Vienna U-Bahn
* The IATA airline designator code for Ural Airlines
* British NVC community U6, "Juncus squarrosus" – "Festuca ovina" grassland, one of the calcifugous grassland communities of the British National Vegetation Classification
* Ultima VI, a computer video game from the Ultima series
* U6, an unemployment figure released by the United States Bureau of Labor Statistics