Jacques Dubois (Latinised as Jacobus Sylvius; 1478 - 14 January 1555) was a French anatomist who was professor of surgery at Collège Royal. He was the first to describe venous valves, although their function was later discovered by William Harvey.

He was the brother of Franciscus Sylvius Ambianus (François Dubois; c. 1483 - 1536), professor of humanities