AH

AH may refer to:
*Albert Heijn a Dutch supermarket chain owned by Ahold.
*Anno Hegirae a Latinization of Hijri year.
*After hours stock trading.
*Alaska Highway
*Authentication Header, a part of the IPsec protocol suite
*Avalon Hill, makers of military-themed board games
*Air handler, Often abbreviated to AHU, is a device used to condition and circulate air
*Alternate History, a subgenre of speculative fiction.
*Artificial Horizon, an aircraft instrument.

Ah may refer to:
*ampere-hour, a unit of electric charge.
* An onomatopoeia for the sound made when one realizes something. In certain spiritual traditions AH may mean:
* Is the first sound made when evoking the sound Aum of the Omkara signification.

aH may refer to:
*attohenry, an SI unit of inductance