General Lord Robert Manners (c. 1721 – 31 May 1782) was an English soldier and nobleman. He was a son of John Manners, 2nd Duke of Rutland and his second wife, Lucy Sherard.
He purchased an ensigncy in the Coldstream Guards on 26 July 1735, and was promoted lieutenant in May 1740. On 22 April 1742, he was promoted captain and lieutenant-colonel in the 1st Foot Guards, and in December 1747, colonel and aide-de-camp to King George II. Manners was returned as Member of Parliament for Kingston-upon-Hull in 1747, and kept the seat for the remainder of his life.
In September 1748, he was appointed colonel of the 15th Light Dragoons, which were shortly thereafter disbanded. On 13 March 1751 he was made colonel of the 36th Regiment of Foot, and was promoted major-general on 7 February 1757, and lieutenant-general on 7 April 1759. He was transferred to the colonelcy of the 3rd (The Prince of Wales's) Dragoon Guards on 6 September 1765. He was promoted general on 25 May 1772 and died on 31 May 1782.
On 1 January 1756 he married Mary Digges (c. 1727–1829), by whom he had several children: