Oak Grove is a home rule-class city[4] adjacent to the Fort Campbell army base in Christian County, Kentucky, in the United States.

[6] The community was named for oak trees near the original town site.

[8] With construction of nearby Fort Campbell in the Second World War, Oak Grove's population grew.

Hopkinsville, the Christian County seat, touches the northwest corner of Oak Grove along Fort Campbell Boulevard (U.S. Route 41 Alternate).

Interstate 24 forms the northeast boundary of Oak Grove, with access from exit 86 (US 41 Alt.)

The city of Clarksville, Tennessee, is along the southern boundary of Oak Grove.

The climate in this area is characterized by hot, humid summers and generally mild to cool winters.