Tsuyoshi Inukai (1855 - 1932) was a Japanese political leader, belonging to constitutional government movements, who became Prime Minister of Japan in 1931 but was assassinated in the May 15 incident of 1932. He was succeeded by Makoto Saito.
He was born into a samurai family. During the Satsuma Rebellion, he was a newspaper reporter with the Army.
His initial political work was with the establishment of the the Rikken Kaishinto party (Constitutional Reform Party), and joined in the daido danketsu (coalition) movement. He was elected a member of the lower house of the Diet in the first general election held in 1890, and was consecutively re-elected until the 18th general election.
He served as education minister in the first Okuma cabinet and communications minister in the second Yamamoto cabinet. In 1922, he organized the Kakushin Club and formed the pro-constitution three-sect cabinet with Takaaki Kato, etc., becoming minister of posts and communications. In 1929, he became president of the Seiyukai (Friends of Constitutional Government Party).