Eysteinn Erlendsson was a 12th-century Norwegian prelate who served as the Archbishop of Nidaros from 1161 until his death in 1188. Born into a noble family in the Trøndelag region, he received his education in Paris at Saint-Victor. During a period of intense civil conflict in Norway, he played a decisive political role by crowning Magnus Erlingsson, which helped establish a new law of succession. He is remembered for his efforts to strengthen the connection between the Norwegian Church and Rome.