9U or 9-U may refer to:
Transportation Air Moldova (former IATA code: 9U), a former airline Yak-9U, a model of Yakovlev Yak-9 Su-9U, a designation of Sukhoi Su-9 9U, a type of Volkswagen Caddy Burundi (aircraft registration code: 9U)
Computing 9U, one of the possible sizes of a rack unit HP 9U, a Windows 3.0 version of the Windows-1252 codepage by Hewlett-Packard printers
See also U9 (disambiguation)