U5 or U-5 may refer to:
Biochemistry U5 spliceosomal RNA mtDNA haplogroup U5, within Haplogroup U
Transport Aviation SkyUp MT (IATA code U5), a Maltese airline subsidiary of SkyUp Airlines Karinou Airlines (former IATA code: U5), former airline of the Central African Republic USA3000 Airlines (former IATA code: U5), former airline based in Pennsylvania, US
Land transport U5 (Berlin U-Bahn), a subway line in Germany U5 (Vienna U-Bahn), a subway line in Austria (under construction) U-5, a Munich U-Bahn subway line in Germany Aiways U5, a 2019 Chinese electric car model Luxgen U5, a 2017 Taiwanese car model Utah State Route 5 (disambiguation), one of two American highways Beijing U5, a Chinese car
Submarines German submarine U-5, several submarines SM U-5 (Germany), the lead boat of the class U-5-class submarine (Austria-Hungary), a class of three built 1908–1911 SM U-5 (Austria-Hungary), the class's lead boat
Other uses U5, a music partnership between the X5 Music Group and Universal labels U5, an unemployment figure released by the United States Bureau of Labor Statistics Ultima V: Warriors of Destiny, a 1988 computer role-playing game
See also 5U (disambiguation) US (disambiguation)