Castel San Pietro Romano is a (municipality) in the Metropolitan City of Rome in the Italian region of Latium, located about east of Rome. In 2017, it had a population of 883.
It is one of I Borghi più belli d'Italia ("The most beautiful villages of Italy") and received the "Comune Riciclone del Lazio" award from Legambiente. It is a member of Cittaslow.
On 12 October 2018, the country had its first honorary citizen, Gina Lollobrigida.