Sakai Tadaaki

, also known as Sakai Tadayoshi, was a Japanese daimyō of the Edo period, and he was a prominent shogunal official. He was also known as by his courtesy titles of Shūri-daibu (1834; and again in 1850); as Wakasa-no-kami; and Ukyō-daibu (1862). He was Obama's last daimyō, holding this position until the feudal domains were abolished in 1871.

Biography Tadaaki was fifth son of Sakai Tadayuki, and became daimyō in 1834 on the retirement of Sakai Tadayori without an heir. His wife was a daughter of Matsudaira Terunobu of Takasaki Domain. In 1840, he was given the courtesy title of Wakasa-no-kami and Lower 4th, Junior grade court rank. In 1842, was appointed a sōshaban and jisha-bugyō simultaneously. The following year was appointed the 48th Kyoto Shoshidai,

Tadaaki was reappointed as the 52nd Kyoto Shoshidai from August 5, 1858, through July 26, 1862.

He resigned again in 1862, this time also from the position of daimyō, adopting Sakai Tadauji, the son of a hatamoto as his heir, and went into retirement. At this time, he also changed his name to Tadatoshi (忠禄). However, with the start of the Boshin War, following the defeat of the Tokugawa shogunate forces at the Battle of Toba-Fushimi, he resumed the post of daimyō and defected to the Imperial side. In 1869, he was appointed imperial governor of Wakasa under the new Meiji government. He died in 1873.