Pottawatomie County (standard abbreviation: PT) is a county located in the U.S. state of Kansas. As of the 2010 census, the county population was 21,604. The county seat is Westmoreland. The county takes its name from the Potawatomi tribe of Native Americans.Pottawatomie County is part of the Manhattan, KS Metropolitan Statistical Area.Among the famous natives of Pottawatomie County are world heavyweight boxing champion Jess Willard and automobile manufacturer Walter Chrysler.