King County is a county located in the U.S. state of Texas. As of the 2010 census, its population was 286, making it the second-least populous county in Texas and the third-least populous of any county in the United States. King County has no incorporated communities. Its county seat is the Census Designated Place of Guthrie. The county was created in 1876 and organized in 1891. It is named for William Philip King, who died at the Battle of the Alamo.