Itagaki Taisuke (板垣 退助 1837–1919) was a Japanese politician and prime minister who was known for his formation of the Aikokusha and the Liberal Party, which were two popular Japanese political parties in the early Meiji Period which soon dissolved. Both were left-wing and liberal/socialist, and when Aikokusha dissolved, Taisuke formed the Liberal Party.

He was the victim of an assassination attempt in 1882. During his era many Japanese politicians were successfully assassinated. He died of old age in 1919.