William Marshall (1796 – 16 May 1872) was a British politician. He served as the Member of Parliament for Petersfield (1826–1830), for Leominster (1830–31), for Beverley (1831–1832), for Carlisle (1835–1847), and for East Cumberland (1847–1868). His younger brothers John and James Garth were both MPs for Leeds. The fourth brother, Henry Cowper, was Mayor of Leeds in 1842–1843. Marshall's daughter, Elizabeth Margaret, was the mother of the diplomat, Sir Cecil Spring Rice.