Alessandro Costantini (ca. 1581–1583, Staffolo – 20 October 1657, Rome) was an Italian baroque composer, maestro di cappella at the Collegium Germanicum. His surviving works include several Latin motets.[1]
He and his brother, the composer, were pupils of Giovanni Bernardino Nanino. His brother-in-law was the countertenor, whose sons, the composers Vincenzo Albrici and, were his nephews.