Guido of Acqui was an 11th-century Italian bishop who led the diocese of Acqui in north-west Italy from 1034 until 1070. Born into the noble Counts of Acquesana family in Melazzo, he was orphaned during his youth and studied in Bologna. His leadership was characterized by efforts to reform the liturgy, spirituality, and moral standards of his clergy. He utilized his personal wealth to alleviate financial burdens within the diocese and to fund various religious and educational initiatives.