Marquess Wen of Wei (died 396 BCE), personal name Wei Si, was the founding marquess of the Wei state. He belonged to the Wei clan, one of the noble houses that dominated Jin politics in the 5th and 6th centuries BC.

He became the leader of the Wei clan in 445 BCE, succeeding his father Viscount Huan, and in 424 BCE adopted the title of "Marquess" (?). In 403 BCE, King Weilie of Zhou