U.S. Route 66 through Williams, Arizona began as a dirt street in the center of town which was later cindered and then paved. Despite some modern encroachments, most of U.S. Route 66 through Williams is lined with properties dating from the historic period. The four block long Williams Historic Business District was listed on the National Register of Historic Places on December 20, 1984.

U.S. Route 66 or U.S. Highway 66 was one of the original highways in the United States Numbered Highway System. It was established on November 11, 1926, with road signs erected the following year. The highway, which became one of the most famous roads in the United States, ran from Chicago, Illinois, through Missouri, Kansas, Oklahoma, Texas, New Mexico, and Arizona before terminating in Santa Monica in Los Angeles County, California, covering a total of 2,448 miles (3,940 km).