Girolamo Diruta (c. 1546 – 1624 or 1625) was an Italian organist, music theorist, and composer. He was famous as a teacher, for his treatise Il Transilvano (Venice, 1st part 1593; 2nd part 1609-10[1]) on counterpoint, and for his part in the development of keyboard technique, particularly on the organ. He was born in Deruta, near Perugia.