[3] Hardin County is part of the Beaumont-Port Arthur, TX metropolitan statistical area.

The county is named for the family of William Hardin (1801-1839), a settler, judge, and postmaster.

The Hardin family cemetery is located north of Liberty.

[6] Hardin County is located on the flat coastal plains of Southeast Texas, roughly 30 mi (48 km) north of the Gulf of Mexico.

The county is largely covered by the dense forest of the Big Thicket.

[12] As of the census[13] of 2000, 48,073 people, 17,805 households, and 13,638 families resided in the county.