Sir William Lane-Mitchell JP (born Mitchell; 24 January 1861 – 20 June 1940) was a Scottish Conservative Party politician and businessman in London. He was elected as the Member of Parliament (MP) for Streatham in 1918, and held the seat until his resignation in 1939 by becoming Steward of the Manor of Northstead. He was also a two-term Mayor of Camberwell between 1906 and 1908 and a magistrate. Lane-Mitchell died in Herne Hill a year after his wife had moved into a nursing home, his death preceding hers by only a few days.