Margaret Cavendish (22 October 1661 – 24 December 1716, London) was the second child of Henry Cavendish, 2nd Duke of Newcastle-upon-Tyne and his wife Frances Pierrepoint.
On 1 March 1690 she married John Holles, 1st Duke of Newcastle-upon-Tyne (of the second creation in 1694, the first creation having become extinct in 1691). They had one child, Lady Henrietta Cavendish Holles (1694–1755), who married the 2nd Earl of Oxford and Mortimer and was mother to Margaret Bentinck, Duchess of Portland.