AH (also Ah or ah) may refer to:
- Ah (digraph), a digraph used in Taa orthography
- Adolf Hitler (1889-1945), Austrian born dictator of Nazi Germany and leader of the NSDAP
- After-hours trading in stock trading
- Air handler, or air handling unit (AHU), a device used to condition and circulate air
- Albert Heijn, a Dutch supermarket chain owned by Ahold
- Ampere-hour, a unit of electric charge
- Anhui, a Chinese province
- Asian Highway
- Attohenry (aH), an SI unit of inductance
- Auction house
- Austria–Hungary, a former European empire
- Hijri year (Anno Hegirae) in the Islamic calendar
- Adenomatous hyperplasia; see endometrial adenomatous hyperplasia and atypical adenomatous hyperplasia
Read more about AH: In Aviation, In Computing, In Entertainment, Similar Glyphs