Hg

HG and Hg may refer to:
* Hg, the chemical symbol for mercury (element) (hydrargyrum).
* mmHg, or Torr, a unit of pressure
* hg, or hectogram, one tenth of a kilogram
* Hg, the Biblical book of Haggai
* Hg, short hand for version control software Mercurial
* HG, defunct magazine; successor to House & Garden (magazine)
* HG, a member of the comedy duo Roy and HG
* HG, the IATA code for the Niki airline
* Hlinka Guard, the militia movement of the Slovak People's Party
* Hyperemesis gravidarum, a severe form of morning sickness
* Hard Gay, or Razor Ramon HG, the performing name of Japanese comedian Masaki Sumitani
* HG, one of the levels used in the Gunpla grading system.
* hg, the command-line interface to the Mercurial source management tool
* Hyperglide - bicycle dérailleur systems
* The alternate name for the game Archer Maclean's Mercury