Giussago is a comune (municipality) in the Province of Pavia in the Italian region Lombardy, located about 20 km south of Milan and about 11 km north of Pavia.

[3] Giussago borders the following municipalities: Borgarello, Bornasco, Casarile, Certosa di Pavia, Lacchiarella, Rognano, San Genesio ed Uniti, Vellezzo Bellini, Zeccone.

Giussago, known in the 15th century as 'Iussagum' was formed by aggregating the many small municipalities of the area.

This union took place between the end of the 19th century and the beginning of the 20th.

Even today in the town of Giussago there are less than one third of the total population of the municipality.