Dr John Marek (born 24 December 1940) is a Welsh politician representing the Wrexham constituency for the Labour Party as Member of Parliament from 1982 to 2001, and as member of the Welsh Assembly from 1999 to 2003, which he served as Deputy Presiding Officer. Of Czech descent, he was the only Czech-speaking member of the British Parliament.

As a result of internal disagreements within the Wrexham Labour Party, he was deselected as the Labour Party's candidate in the Welsh Assembly elections of 1 May 2003, as a result of which he stood for the John Marek Independent Party and was successfully elected, defeating the official Labour Party candidate, Marek's former secretary, Lesley Griffiths. Were it not for the very low turnout in the Assembly election, Marek would certainly have lost his seat, as his re-election as a JMIP AM was more to do with his undoubted ability to mobilise his hard-core supporters, than any discontent with the Morgan executive(as the results across Wales showed there was very little), or as any reputation as a good AM.