 lamar is a city and county seat of barton county, missouri, united states. as of the 2010 census, the city population was 4,532.{{cite web|title=2010 city population and housing occupancy status|url=http://factfinder2.census.gov/faces/tableservices/jsf/pages/productview.xhtml?pid=dec_10_pl_gctpl2.st13&prodtype=table|publisher=u.s. census 
Cities_in_Barton_County,_Missouri County_seats_in_Missouri Populated_places_established_in_1852