Aux or AUX may refer to:
Science and technology AUX (company), a Chinese electronics manufacturer Auxiliary connector or AUX jack, typically used for analog audio signals Aux/IAA repressors, related to auxin plant hormones
Computing AUX: (for auxiliary), a DOS text device AUX (CONFIG.SYS directive), changes assignment for AUX: device in DR-DOS A/UX, a Unix operating system by Apple
Other uses Auxiliary (disambiguation) (abbreviation) Aux (TV channel), a Canadian music TV channel Araguaína Airport (IATA airport code), Tocantins, Brazil