Ajalvir (Spanish pronunciation: [axalˈβiɾ]) is a town and municipality in the Autonomous Community of Madrid in central Spain, located 26 kilometres (16 mi) north-east of Madrid and 12 kilometres (7.5 mi) from Alcalá de Henares.

The name Ajalvir is believed to have derived from the Arabic al-jalaoui, meaning isolated or separated.

The town is crossed right by its centre by a creek, possibly a tributary of the "de la Huelga" stream.

The area is slightly hilly, the highest peak is called "Cabeza Gorda" (fat head) of 767 meters, close to the "cerro del tordo" (hill of the thrush).

This article about a location in the Community of Madrid, Spain is a stub.