Captain William Stephen Sanders CBE^[1] (2 January 1871 – 6 February 1941) was a British Labour Party politician.

Sanders married Beatrice Martin, who later became a prominent suffragette.^[2] Both were active members of the Union of Ethical Societies (now Humanists UK), with Sanders writing and lecturing widely on its behalf, and acting as chair of the Council.^[3]

Sanders unsuccessfully contested Portsmouth in 1906 and in January 1910. He was elected Member of Parliament (MP) for Battersea North at the 1929 general election and served as Financial Secretary to the War Office from 1930 to 1931, but lost his seat in 1931. He was re-elected for Battersea North at the 1935 general election, and held the seat until his resignation from the House of Commons in 1940^[4] by accepting the post of Steward of the Manor of Northstead,^[5] a notional office-of-profit under the crown.