Lumberton is a city in Hardin County, Texas, United States. The population was 13,554 at the 2020 census, up from 11,943 at the 2010 census. …Lumberton is a city in Hardin County, Texas, United States. The population was 13,554 at the 2020 census, up from 11,943 at the 2010 census. Lumberton is the home of Village Creek State Park. The city is part of the Beaumont–Port Arthur metropolitan area.