William Samuel Plenderleath Lithgow (18 February 1920 – 8 August 1997) was an English first-class cricketer. Lithgow played first-class cricket before the Second World War for Oxford University. After the war he embarked on a career as a professional soldier, serving in both the Royal Artillery and the 10th Royal Hussars until 1968. He later served as a bodyguard to Elizabeth II in the Honourable Corps of Gentlemen at Arms from 1970 to 1990.