The Clarksville Metropolitan Statistical Area is defined by the United States Census Bureau as an area consisting of four counties – two (Montgomery and Stewart) in Tennessee and two (Christian and Trigg) in Kentucky – anchored by the city of Clarksville, Tennessee. A July 1, 2018 estimate placed the population at 307,820. As of 2009, the Clarksville Metropolitan Statistical Area is the 167th largest MSA in the United States.