Denzil Onslow of Stoughton (c. 1698 – 15 November 1765) of Mickleham, Surrey was a British politician. A member of the influential Onslow family of Surrey, he held a number of lucrative Government posts, and died owing a relatively large sum to the Treasury through mismanagement of his accounts. He was the son of Richard Onslow (d. 1719) and Sarah Manning, and grandson of Sir Henry Onslow, of Drungewick, who was a younger son of Sir Richard Onslow. His mother was Sarah, daughter of Thomas Calvert.