Cook County is a county located in the south central portion of the U.S. state of Georgia. As of the 2020 census, the population was 17,229. The county seat is Adel. The constitutional amendment to create the county was proposed July 30, 1918, and ratified November 5, 1918. It is named for former Civil War general Philip Cook of the Confederate States Ar…Cook County is a county located in the south central portion of the U.S. state of Georgia. As of the 2020 census, the population was 17,229. The county seat is Adel. The constitutional amendment to create the county was proposed July 30, 1918, and ratified November 5, 1918. It is named for former Civil War general Philip Cook of the Confederate States Army.