Emperor Wu of (Liu) Song (363–422), personal name Liu Yu, courtesy name Dexing, nickname Jinu, is the founding emperor of the Chinese dynasty Liu Song.

He comes from a humble background, but becomes prominent after leading a rebellion in 404 to overthrow Huan Xuan, who had usurped the Jin throne in 403.

After that point, using a mixture of political and military skills, Liu Yu gradually concentrates power in his own hands while expanding Jin's territory.

In 420, he forces Emperor Gong of Jin to yield the throne to him, thus ending Jin and establishing Song.

He rules only briefly, for two years, before dying and passing the throne to his son, Emperor Shao of Liu Song.