Jacques-Timothée Boucher, Sieur de Montbrun, anglicized as Timothy Demonbreun (/dəˈmʌmbriən/; 23 Mar 1747, Montreal, Québec, Canada – Oct 1826 Nashville, Tennessee, USA) was a French-Canadian fur trader, an officer of the American Revolution, Lieutenant-Governor of the Illinois Territory and is known as the "first citizen" of Nashville, Tennessee.