North Fork Umatilla Wilderness, Protected wilderness area in Umatilla National Forest, Oregon, United States.

North Fork Umatilla Wilderness is a protected wilderness area within Umatilla National Forest in northeastern Oregon. It is made up of deep canyons, forested slopes, and open plateaus, all crossed by a network of hiking trails.

The North Fork Umatilla Wilderness was designated by the US Forest Service in 1984 under the Wilderness Act, protecting 20,144 acres (8,152 ha) in Umatilla and Union counties. It is the smallest wilderness area in northeastern Oregon, lying inside Umatilla National Forest in the Blue Mountains.

The Nez Perce and other Native peoples traveled and hunted across these lands for generations. Many of the hiking trails today follow the same routes those communities used through the canyons and across the plateaus.

The lower canyon trails tend to open earlier in spring, while the higher routes stay accessible well into fall. Weather can shift quickly at any elevation, so layered clothing and sturdy footwear are worth bringing regardless of the season.

The North Fork Umatilla River holds bull trout and steelhead, and several streams in the wilderness carry native trout, with a few supporting spawning steelhead. The main river is designated catch-and-release only, so anglers release every fish they land.