Almazul is a municipality in the province of Soria, within the autonomous community of Castile and León, Spain. It lies in the eastern part of the province, in the region of Castile known for its sparsely populated rural municipalities.
The town's name derives from Arabic, from "al Mahsul," a term referring to the vertical movement of water. This name is connected to the source of the river Henar, which rises in the area.