Prescott is a city in and the county seat of Yavapai County, Arizona, United States. As of 2020 Census, the city's population was 45,827. I…Prescott is a city in and the county seat of Yavapai County, Arizona, United States. As of 2020 Census, the city's population was 45,827. In 1864, Prescott was designated as the capital of the Arizona Territory, replacing the temporary capital of Fort Whipple. The territorial capital was moved to Tucson in 1867. Prescott again became the territorial capital in 1877, until Phoenix became the capital in 1889.