Emperor Yōmei (用明天皇) (died 587) was the 31st imperial ruler of Japan. He ruled from 585 to 587.

He was called Tachibana no Toyohi no mikoto (橘豊日命, Lord Tachibana no Toyohi) in Nihonshoki. On occasion he was also referred to as Prince Ōe (大兄皇子, literary crown prince or succession right holder) and Prince Ikebe (池辺皇子) named after the place in which he lived. He ascended to the throne after the death of his half brother, Bidatsu.

He was the fourth son of the Emperor Kimmei by Kitashihime, a Soga woman and daughter of Soga no Iname . His three consorts were recorded, including his wife, who was his half-sister Princess Hashihoto no Anahobe whose mother was another daughter of Iname. Princess Hashihito no Anahobe became his empress, and she bore him five sons, including Prince Shotoku, the crown prince of the Empress Suiko.

The influential courtiers of the court of Bidatsu, Mononobe no Moriya and Soga no Umako remained in their position. Umako was the son of Iname, and therefore Yomei's cousin as well.

Yomei was in favor of Buddhism. Because of the shortness of his reign, Yomei didn't cause any radical changes, but his inclination towards Buddhism created tension with the Shintoists. Moriya, the most influential Shintoist in the court, conspired with Prince Anahobe, a brother of Yomei; after Yomei's death, they rebelled and attempted to seize the throne, but were unsuccesful. Some assumed Yomei was assassinated by those two.