Phillips County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 4,530. The county seat is Holyoke. The county was named in honor of R.O. Phillips, a secretary of the Lincoln Land Company, who organized several towns in Colorado.

Colorado's 4th congressional district is a congressional district in the U.S. state of Colorado. Located in the eastern part of the state, the district encompasses most of the rural Eastern Plains as well as portions of the Colorado Front Range including Loveland, Highlands Ranch, Castle Rock, and Parker.