| Inoue Masaoto | |
| Native Name: | 井上 正巳 |
| Native Name Lang: | jp |
| Birth Date: | 10 February 1856 |
| Allegiance: | Shimotsuma Domain |
| Rank: | Daimyō |
| Battles: | Boshin War |
(February 10, 1856 – September 14, 1921) was a Japanese daimyō of the Edo period, who served as the last lord of the Shimotsuma Domain. His court title was Iyo no kami. Under his leadership, Shimotsuma fought on the side of Aizu during the Boshin War.
Masaoto was created shishaku (viscount) in the Meiji-era kazoku nobility.