Cornelis, or Cornelius de Witt (1623-1672) was a Dutch statesman.

Brother of Johan de Witt, Cornelis was born at Dort . In 1650 he became burgomaster of Dort and member of the states of Holland and West Friesland. He was afterwards appointed to the important post of ruwaard or governor of the land of Putten and bailiff of Beierland .

He associated himself closely with his greater brother, the grand pensionary, and supported him throughout his career with great ability and vigour. In 1667 he was the deputy chosen by the states of Holland to accompany Admiral de Ruyter in his famous raid on the Medway. Cornelis de Witt on this occasion distinguished himself greatly by his coolness and intrepidity. He again accompanied De Ruyter in 1672 and took an honorable part in the great battle of Solebay against the united English and French fleets. Compelled by illness to leave the fleet, he found on his return to Dort that the Orange party were in the ascendant, and he and his brother were the objects of popular suspicion and hatred.

He was assassinated by the same lynch mob that killed his brother.