Baden, sometimes unofficially, to distinguish it from other Badens, called Baden bei Zürich or Baden im Aargau, is a town and a municipality in Switzerland. It is the main town or seat of the district of Baden in the canton of Aargau. Located 25 km (16 mi) northwest of Zürich in the Limmat Valley mainly on the western side of the river Limmat, its mineral hot springs have been famed since at least the Roman era. Its official language is German, but the main spoken language is the local Alemannic Swiss-German dialect. As of 2018 the town had a population of over 19,000.

Aargau, more formally the Canton of Aargau, is one of the 26 cantons forming the Swiss Confederation. It is composed of eleven districts and its capital is Aarau.