Inarzo is a comune (municipality) in the Province of Varese in the Italian region Lombardy, located about northwest of Milan and about southwest of Varese. As of 2011 it had a population of 1073 and an area of .
Inarzo borders the following municipalities: Bodio Lomnago, Cazzago Brabbia, Casale Litta, Varano Borghi, Ternate, Biandronno.