3U or 3-U may refer to:
- Sichuan Airlines's IATA code
- A type of Rack unit
- Zerstörergeschwader 26, from its historic Geschwaderkennung code with the Luftwaffe in World War II
- A CubeSat measuring 30×10×10 cm
- The acronym for the third (3rd) catalog of Uhuru x-ray sources
See also
Topics referred to by the same termThis disambiguation page lists articles associated with the same title formed as a letter–number combination.If an internal link led you here, you may wish to change the link to point directly to the intended article. Category: