Atto of Pistoia (1070-22 May 1153) was a Spanish-born 12th-century prelate and historiographer in Italy. He was born at Badajoz in the Spanish region of Estremadura in 1070. He became Abbot of Vallombrosa (in Tuscany) in 1105, and in 1135 was made Bishop of Pistoia, also in Tuscany. He wrote lives of St. John Gualbert and St. Bernard of Vallombrosa, bishop of Parma. In 1145 he transferred to Pistoia certain relics of the Apostle St. James of Compostella. His correspondence on that occasion is found in Ferdinando Ughelli, Italia sacra, VII, 296.