Dennis Hopper and Michelle Phillips: 8 days
The "Easy Rider" actor was married five times in his life, with by far the shortest marriage coming in 1970 to The Mamas & the Papas singer. In what was the second marriage for both of them, Hopper and Phillips were wed on Oct. 31, 1970. She ended up filing for divorce on Nov. 8, 1970. Years later, Hopper told the New York Times, "Seven days were pretty good. But the eighth was bad."