  '''AH''' (also '''Ah''' or '''ah''') may refer to: * AH Adeel Hina * ''anno Hegirae'' (in the year of the Hijra), a year in the Islamic calendar * Adenomatous hyperplasia * Ah (computer virus) * AH register, the high byte of an X86 16-bit AX register  * A-ha, a New Wave/Synthpop band from Norway * Ah (digraph) * After-hours trading in stock trading * AH-1 Cobra, a model of attack helicopter * AH-64 Apache, a model of attack helicopter * Adolf Hitler * Air handler, Often abbreviated to AHU, is a device used to condition and circulate air * Albert Heijn, a Dutch supermarket chain owned by Ahold  * Alternate History, a subgenre of speculative fiction * ''Anno Hegirae'' (Hijri year) in the Islamic calendar  * Ampere-hour, a unit of electric charge. * Anhui, cf. CPG website * Arcana Heart. a video series * Artificial Horizon, a cockpit instrument (Aviation) * an attohenry, from the Henry (unit), an SI unit of inductance * Auction house * Austria–Hungary, a former European empire * Authentication Header, a part of the IPsec protocol suite * Avalon Hill, makers of military-themed board games    de:AH es:Ah eo:AH fa:AH (ابهام‌زدایی) fr:AH ko:AH id:AH it:AH sw:AH lt:AH nl:AH ja:AH no:AH pl:Ah pt:AH ru:AH sl:AH fi:Ah sv:AH zh:AH