Alquézar (Aragonese: Alquezra)[3] is a municipality in the province of Huesca, in the autonomous community of Aragon, Spain.

Situated on a limestone outcrop of the Eocene age to the west of the canyon of the Rio Vero in the Sierra y Cañones de Guara Natural Park, the village grew up around a castle and the Collegiate church of Santa Maria, which was consecrated in 1099.

The name of the village comes from the Arabic القصر al qaçr for "fort" or "castle" (renamed as Alcazar in Spanish).

Since Alquézar is situated in the Sierra y Cañones de Guara Natural Park, there are various campsites in the local area to cater to outdoor enthusiasts.

A good example is the cave at Arpán on the A-2205 road heading north towards Bárcabo.