The transition from Sui to Tang refers to a period in which the Chinese dynasty Sui Dynasty disintegrates into a number of short-lived states, some ruled by former Sui officials and generals and some by agrarian rebel leaders; those states are then consolidated into the Tang Dynasty, founded by the former Sui general Emperor Gaozu of Tang (Li Yuan).

The period roughly spans from 613, when Emperor Yang of Sui launches his first of three campaigns against Goguryeo, leading to a number of desertions from the army and the start of agrarian rebellions against Sui, to 628, when Emperor Gaozu's son Emperor Taizong of Tang (Li Shimin) destroys the Liang state ruled by the agrarian rebel ruler Liang Shidu and reunifies China.