Jean-Marie Demange (23 July 1943 in Toulouse – 17 November 2008) was a French member of Parliament. A member of the UMP he was Mayor of Thionville for 13 years, serving in that capacity from 25 June 1995 to 21 March 2008. He had been distraught after losing the 2008 election to a Socialist and committed suicide by gunshot after he killed his mistress following a heated argument.