Thénia (also written as Thenia) is a town located in northern Algeria. It serves as the chief town within the daïra of Thénia, situated in the wilaya of Boumerdès. The municipality has a population of approximately 40,000 inhabitants.
The name Thénia is historically derived from "Theniet Beni Aicha," which is the Arabic translation of the Kabyle Berber toponym Tizi n At Ɛica. This location refers to a steep-sided pass that measures roughly 800 metres (2,600 ft) at its narrowest point. The pass is notable for marking the geographical transition between the Mitidja and Grande Kabylie regions.