- Death: 1582
- Other names: Saitô Shingorô, Saitô Toshioki
- Distinction: Oda retainer
- Japanese: 斎藤 長龍 (Saitô Nagatatsu)
Nagatatsu was a younger son of Saitô Dosan. He was taken from Mino province to avoid the fate of his elder brothers, slain by Saitô Yoshitatsu, and entered the protection of Oda Nobunaga. He was later married to a daughter of a certain Satô Kii no kami and was given a fief in Mino province (taken by the Oda in 1567). He served in various campaigns for Nobunaga and in 1582 was killed alongside Oda Nobutada at Nijô following Nobunaga's death at the hands of Akechi Mitsuhide.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005