HX or Hx may refer to:
- Hx or hx, is a digraph in the Esperanto x-system orthography, representing the consonant sound or, normally spelled as Ĥ or ĥ in the Esperanto alphabet
- HX (convoy), a convoy code used during World War II
- HX DOS Extender, a free software product
- Hong Kong Airlines IATA code
- Hx or Hx, shorthand for medical history
- an abbreviation of a hydrogen halide
- The HX postcode area, covering Halifax, Elland, Hebden Bridge and Sowerby Bridge in England.
- Hummer HX, a concept automobile produced by HUMMER
- Dolby HX and Dolby HX Pro, dynamic range headroom extension systems for analog recording on magnetic tape.
- .hx files are for the haXe programming language
- Hacking, an abbreviation among online gamers