Lucius Calpurnius Piso Frugi (c. 180 – 112 BC) was a Roman politician and historian. He created the first permanent jury court in Rome (quaestio perpetua) to try cases related to provincial corruption during his plebeian tribunate in 146 BC. He also fought, not entirely successfully, in the First Servile War. He was consul in 133 BC and censor in 120 BC.
Later in life, he wrote the Annales, a history of Rome from its foundation through to at least 146 BC and probably his own time; only 49 fragments of the Annales survive, preserved in other works. Consisting of seven or eight books, it was the first history to split up Roman history into a year-by-year account.