Sir Robert Marney (ca. 1319 – 1400), of Layer Marney, Essex, and Kingsey, Buckinghamshire, was a 14th-century English politician. He was the son of Sir William Marney and his wife Katherine Venables. He has been described as "disreputable local gentry" by one 21st-century historian and was accompanied John Fitzwalter, 2nd Baron FitzWalter on various violent and criminal acts in the Colchester area.