Akai Tadayasu served as a bushō in the Azuchi-Momoyama period and hatamoto in the Edo period.

Tadayasu was born in 1582 as the eldest son of Akai Tadaie.  In 1598, he became a servant of Tokugawa Ieyasyu.  In 1600, he deployed for the Aizu seibatsu, or the Subjugation of Aizu.  Late in 1600, he joined his father, Tadaie, to fight on behalf of the Eastern Army at the Battle of Sekigahara.  In 1602, Tadayasu was awarded of fief of 2,000 koku in the Yamabe District of Yamato Province.  He succeeded his father as head of the clan in 1605, and assigned his fief of 1,000 koku to his younger brother, Akai Kimio.   In 1616, he governed a fief of 2,000 koku in the Toichi District of Yamato.  In 1617, he was appointed along with Katagiri Sadataka as commissioners to oversee the reconstruction of the Shitennō Temple that had been laid waste in the Siege of Ōsaka.  The construction was completed in 1618, while a celebration marking the opening of the temple was held in 1623.  In 1634, Tadayasu accompanied Tokugawa Iemitsu on travel to Kyōto.