Mountain Longleaf National Wildlife Refuge, National wildlife refuge in Calhoun County, Alabama, US.

Mountain Longleaf National Wildlife Refuge is a protected area in northeastern Alabama that spans over 9,000 acres of forested mountain slopes. The landscape is dominated by longleaf pine forests growing at elevations around 1,400 feet, with hiking trails and observation points distributed throughout the accessible portions.

The refuge occupies the former military training grounds of Fort McClellan in the Choccolocco range, part of the Ridge and Valley section of the Appalachians. It was created to protect some of the last montane longleaf pine (Pinus palustris) stands in the southeastern United States. The refuge also administers the Cahaba River and Watercress Darter refuges.

The refuge's name refers to the montane longleaf pine (Pinus palustris) stands it protects, among the last of their kind in the southeastern United States. The land was the military training ground of Fort McClellan before becoming a refuge, and a single information kiosk for hunters stands at the junction of Bain's Gap Road and Ridge Road South.

About 3,000 of the refuge's 9,016 acres are open to the public during daylight hours; the rest stays closed until environmental cleanup from the Fort McClellan era is finished. Trails are unmarked and facilities are limited to a single information kiosk at the junction of Bain's Gap Road and Ridge Road South. The terrain climbs the Choccolocco range to about 430 metres, so plan for slopes and carry water.

The refuge protects one of the last montane longleaf pine (Pinus palustris) ecosystems in the southeastern United States, growing on the Choccolocco range of the southern Appalachians. It also administers two other refuges, Cahaba River and Watercress Darter.