Colle San Magno (locally Glio Colle) is a comune (municipality) in the Province of Frosinone in the Italian region Lazio, located about 110 kilometres (68 mi) southeast of Rome and about 30 kilometres (19 mi) southeast of Frosinone.

Its name refers to St. Magnus of Anagni.

In 1796 it was acquired by the Kingdom of Naples.

Attractions include the medieval castle, the old asphalt mines and the church of S.M.

This Lazio location article is a stub.