Matthew Lyon (July 14, 1749 – August 1, 1822) was an Irish-born American printer, farmer, soldier and politician, who served as a United States Representative from both Vermont and Kentucky. Lyon represented Vermont in Congress from 1797 to 1801, and represented Kentucky from 1803 to 1811. His tenure in Congress was tumultuous. He brawled with one Congressman, and was jailed on charges of violating the Sedition Act, winning re-election to Congress from inside his jail cell. Lyon's trial, conviction, and incarceration boosted his status among the fledgling Democratic-Republican Party as a free-speech martyr.