6U

6U or 6-U may refer to:

Aviation

 * Air Ukraine (IATA code: )
 * PW-6U, a model of Politechnika Warszawska PW-6 glider
 * HY-6U, a model of Xian H-6 jet bomber

Other technologies

 * 6U, a rack unit configuration of 10½-inch depth
 * RG-6/U coaxial electrical cable
 * 6U, a model of Zenit Soviet spy satellite