Saitō Toshinaga (斎藤 利永, died June 16, 1460) was a daimyō during Japan's Muromachi period. He was the son of (斎藤宗円), shugo of Mino Province, and the older brother of Saitō Myōchin, making him the uncle of the warlord Saitō Dōsan. By his first wife, he was the father of (斎藤利藤) and (斎藤典明). His second wife, who was born into the Akamatsu clan, birthed (斎藤妙純), (斎藤利安), (斎藤利綱) and (斎藤利隆).