Pignataro Interamna is a town and comune located in the province of Frosinone within the Lazio region of Italy. It serves as a local administrative center situated in the central part of the country.
The municipality takes its name from the ancient Latin colony of Interamna Lirenas. This settlement was established by the Romans following their conquest of Casinum, which was an ancient Oscan city. The historical origins of the area are rooted in this period of Roman expansion and colonization.