Williams is a city in Coconino County, Arizona, United States, located west of Flagstaff. Its population was 3,023 at the 2010 census. It lies on the routes of Historic Route 66 and Interstate 40. It is also the southern terminus of the Grand Canyon Railway, which takes visitors to Grand Canyon Village. Also known as the "Gateway to the Grand Canyon", Williams was the last city on Historic Route 66 to be bypassed by Interstate 40. The Historic Downtown District covers six square blocks.