John Wadsworth (1850 – 10 July 1921) was a British trade unionist and Liberal or Lib-Lab politician. Born in West Melton in the West Riding of Yorkshire, Wadsworth worked as a coal miner and was elected checkweighman. He joined the Yorkshire Miners Association, a constituent part of the Miners Federation of Great Britain (MFGB), rising to become the Yorkshire Association's general secretary, then in 1904 its president. Wadsworth was elected as the Lib-Lab Member of Parliament (MP) for Hallamshire at the 1906 general election. In 1909, with the other MFGB-sponsored MPs, he joined the Labour Party, retaining his seat in his new colours. In 1915 he resigned the Labour whip and re-joined the Liberals. He continued as MP until the seat's abolition for the 1918 general election.