Alerre is a municipality in the province of Huesca, in the Aragon region of northeastern Spain. It is a small settlement located in the comarca of Hoya de Huesca, near the city of Huesca itself.
The municipality is sparsely populated, with 201 inhabitants recorded as of 2018. Like many villages in this part of Aragon, it is a rural community whose modest size reflects the broader pattern of small municipalities across the province of Huesca.