Hakalau Forest National Wildlife Refuge, Nature reserve in Hawaii County, United States

Hakalau Forest National Wildlife Refuge is a nature reserve in Hawaii County that spans across the slopes of Mauna Kea. The forest consists of native montane rainforest with Koa and red-blossomed Ohia trees that form closed-canopy sections in places.

The U.S. Fish and Wildlife Service established this protected area in 1985 to safeguard endangered Hawaiian forest birds and their rainforest environments. The creation responded to the decline of many native species and the need to preserve critical habitats.

The name Hakalau comes from the Hawaiian word for "many perches," referring to the branches where native birds once gathered. Eight of the 14 native bird species recorded in the refuge are endangered, including the ʻalalā (Hawaiian crow), which is now extinct in the wild; the Kona Forest Unit was bought in 1997 partly to protect its habitat.

The refuge currently restricts self-guided activities to prevent disease spread through contaminated soil on vehicles and clothing. Visitors should check access rules in advance and follow staff guidance during their visit.

The Pua Akala Cabin inside the refuge was nominated to the National Register of Historic Places in August 2008. The Kona Forest Unit, added in 1997 on the western slopes of Mauna Loa, was created partly to protect habitat for the ʻalalā, a crow now extinct in the wild.