Saltpeter (or saltpetre) is the mineral form of potassium nitrate (KNO<sub>3</sub>), a chemical compound.
It may also sometimes refer to:
- Sodium nitrate (NaNO<sub>3</sub>), a compound
- Chile saltpeter or nitratine, the mineral form
- Norwegian saltpeter or calcium nitrate (Ca(NO<sub>3</sub>)<sub>2</sub>)
- Magnesium nitrate (Mg(NO<sub>3</sub>)<sub>2</sub>)<!--fails WP:DABMENTION-->
See also
- Saltpetre Republic, a term used in Chilean historiography for the 1879–1914 period
- Salpeter (disambiguation)