Lorenzo Masini (di Masi) (Lorenzo da Firenze) (Laurentius de Florentia) (died 1373) was an Italian composer and music-teacher. Born in Florence, he belonged to the second generation of the trecento, and is represented in the Squarcialupi Codex. He was a canonicus at San Lorenzo, Florence, from 1348 until his death (Gallo). His circle probably included Landini and Paolo.