The Saitō clan (斎藤氏 Saitō-shi) was a Japanese clan in Mino province. The Saitō clan itself claimed to be descended from Fujiwara Toshihito.
Saitō Dōsan (1494-1556) was the father-in-law of Oda Nobunaga and the clan's most famous daimyō. Dōsan was attacked by his adopted son Saitō Yoshitatsu and died in battle.
Saitō Tatsuoki was Yoshitatsu's son and was finally defeated at the Battle of Inabayama in 1567 by Oda Nobunaga. Tatsuoki fled and died a few years later making the clan disappear.