Yuwen Huaji (died 619) is a general of the Chinese dynasty Sui Dynasty who, in 618, leads a coup against Emperor Yang of Sui, killing him.

He subsequently declares Emperor Yang's nephew Yang Hao and leads Emperor Yang's elite Xiaoguo Army north, but is then repeatedly defeated by Li Mi, Li Shentong, and finally Dou Jiande.

Believing that his defeat is near and wanting to be emperor before his ultimate defeat, he poisons Yang Hao and declares himself the emperor of a Xu state.

Dou captures him in 619 and kills him.