William Thomas (c. 1850 – after 1892) was a British Liberal politician and solicitor who served as the Member of Parliament (MP) for the Carnarvon Boroughs constituency from 1890 to 1892.
Born in Manchester, Thomas pursued a career in law, becoming a solicitor. His political career saw him contest the Carnarvon Boroughs seat in a by-election in 1890. He was successfully elected, representing the Liberal Party. His tenure as MP was brief, lasting until the 1892 general election, where he lost his seat to David Lloyd George, who would later become Prime Minister. Thomas's period in Parliament was notable for being the predecessor to Lloyd George's long and impactful career representing the same constituency.