| Toshitsugu Saito | |
| Native Name Lang: | ja |
| Office1: | Director-General of the Japan Defense Agency |
| Primeminister1: | Junichiro Koizumi |
| Term Start1: | 5 December 2000 |
| Term End1: | 26 April 2001 |
| Predecessor1: | Kazuo Torashima |
| Successor1: | Gen Nakatani |
| Office2: | Member of the House of Representatives |
| Constituency2: | Shizuoka 2nd (1986–1996) Shizuoka 5th (1996–2003) Tōkai PR (2003–2009) |
| Term Start2: | 6 July 1986 |
| Term End2: | 21 July 2009 |
| Birth Date: | 27 December 1944 |
| Birth Place: | Fuji, Shizuoka, Japan |
| Party: | Liberal Democratic |
| Alma Mater: | Sophia University Waseda University University of Washington |
is a Japanese politician of the Liberal Democratic Party, a member of the House of Representatives in the Diet (national legislature). A native of Fuji, Shizuoka and graduate of Sophia University, he attended Waseda University for graduate study and business school at the University of Washington in the United States. He was elected for the first time in 1986.
From 2001 to 2002 he was Director General of the Japan Defense Agency (now Minister of Defense).