Torii Tadaharu (鳥居 忠春, 1624 – September 2, 1663) was a Japanese daimyō of the early Edo period who ruled the Takatō Domain in Shinano Province (modern-day Nagano Prefecture).
As his father died before a successor was named from among his sons, the Torii family's holdings were confiscated.
However, because of his grandfather Torii Mototada's distinguished service, the family name was restored, and Tadaharu was made lord of the Takatō fief, with an income of 32,000 koku.
Tadaharu was first famed for his wise rulership of Takatō; however, his rule soon became oppressive, especially after he killed seven of his senior retainers who admonished him.
In 1663, while serving at Osaka Castle, Tadaharu was murdered by his doctor Matsui Jukaku.