Robert Grosvenor, 1st Marquess of Westminster, KG (22 March 1767 – 17 February 1845) was the son of the 1st Earl Grosvenor, whom he succeeded in 1802 as 2nd Earl Grosvenor. He was created Marquess of Westminster in 1831. He was an English Member of Parliament (MP) and an ancestor of the modern-day Dukes of Westminster. Grosvenor continued to develop the family's London estates, he rebuilt their country house, Eaton Hall in Cheshire where he also restored the gardens, and built a new London home, Grosvenor House. He maintained and extended the family interests in the acquisition of works of art, and in horse racing and breeding racehorses.