Poggio San Lorenzo is a comune, or municipality, situated in the Province of Rieti within the Italian region of Latium. It is located approximately 50 kilometres (31 mi) northeast of Rome and about 15 kilometres (9 mi) south of the city of Rieti.
As a local administrative division, it serves as a distinct geographical entity in the Rieti province. The municipality is defined by its position within the central Italian landscape, situated between the capital city of Rome and the provincial seat of Rieti.