William Marshall (1796 – 16 May 1872) was a British politician.

He served as the Member of Parliament for Petersfield (1826–1830),^[1] for Leominster (1830–31),^[2] for Beverley (1831–1832),^[3] for Carlisle (1835–1847),^[4] and for East Cumberland (1847–1868).^[5]

He was the eldest son of the wealthy industrialist John Marshall who introduced major innovations in flax spinning and built the celebrated Marshall's Mill and Temple Works in Leeds, West Yorkshire.^[6] Their family name may have inspired the character of Richard Marshall in the 1968 film Witchfinder General, which is set in that area during the English Civil War.

A sister, Julia Anne Elliott, was a hymnwriter; she married Henry Venn Elliott, who was the brother of Charlotte Elliott, another hymnwriter. William's younger brothers John and James Garth were both MPs for Leeds.^[7] The fourth brother, Henry Cowper, was Mayor of Leeds in 1842–1843.^[6] Marshall's daughter, Elizabeth Margaret, was the mother of the diplomat, Sir Cecil Spring Rice.^[8]