Millen is a city in, and the county seat of, rural Jenkins County, Georgia, United States. The population was 3,492 at the 2000 census, a decline of 8.3% since 1990, during a decade in which the state's population grew overall by 26.4%.The city is intersected by U.S. Route 25 and State Route 17 and the proposed Interstate 3 will pass nearby.