Donatus of Fiesole was an Irish priest, poet, and educator who served as the Bishop of Fiesole during the ninth century. Born in Ireland to noble parents, he likely studied at the monastic school of Inishcaltra before traveling to Italy. He was elected to his bishopric in 829, following reports of miraculous signs in the cathedral. Throughout his forty-seven years of service, he acted as a teacher of grammar and metrical composition in Florence, a diplomat for various Italian rulers, and a defender of his church's rights.