Monument Rock Wilderness, Protected wilderness area in eastern Oregon, United States.

Monument Rock Wilderness is a protected natural area in eastern Oregon featuring deep canyons and forests of ponderosa pine, Douglas fir, and white fir trees. The landscape rises from river valleys into higher elevations, creating diverse terrain for visitors to explore.

Congress designated the Monument Rock Wilderness in 1984; it covers 19,650 acres (7,950 ha) in the Malheur and Wallowa–Whitman national forests. The Malheur National Forest itself had been established on 13 June 1908. A separate wilderness, Strawberry Mountain, was set aside in the same forest in 1964.

The name comes from Monument Rock, a landmark within the wilderness, and the area lies in the Blue Mountains of Malheur and Wallowa–Whitman national forests. Congress designated it in 1984, and about 15 miles of trails are maintained for hikers. The wilderness also holds the headwaters of the Little Malheur River and the upper drainages of the South Fork of the Burnt River.

Marked trails crisscross the wilderness with varying difficulty levels for visitors of all abilities. The best experience comes early in the day when the forest is quieter and fewer people are on the paths.

In 2000, researchers investigating unexplained tree deaths in the surrounding Malheur National Forest identified a single Armillaria ostoyae fungus covering about nine square kilometres, estimated at 7,567 to 35,000 tonnes and 1,900 to 8,650 years old. It is the largest known organism by area.