The toponym refers to the castellanze (plural form, singular castellanza), defensive territorial unities who rose around castles and other strong points in the then county of Seprio.

The town is renowned for its in 1991 founded private University Carlo Cattaneo (also known as LIUC).

The town has a population of approximately 15,000 inhabitants, more precisely 14,516 in 2019,[4] and since the late nineteenth century has been one of the main industrial centres in the province of Varese.

With the beautiful backdrop of the Alps and the famous Italian lakes Lago Maggiore and Lago di Como, the province of Varese is also home to 23,000 manufacturing and craft industries that export over 30% of their products worldwide and generate employment to approximately 175,000 people.

[5] In the town, there are several buildings : We can find different schools : The local football club USD Castellanzese was founded in 1921.