The Mogollon Rim is a topographical and geological feature running across Arizona, extending approximately 400 miles (650 km) from northern Yavapai County eastward to the Mogollon Mountains in southwest New Mexico. The Rim is an escarpment defining the southwestern edge of the Colorado Plateau, and along its central and most spectacular portions is characterized by high limestone and sandstone cliffs. It was formed by erosion and faulting, and dramatic canyons have been cut into it, including Sycamore Canyon, Oak Creek Canyon, West Clear Creek Canyon, Fossil Creek Canyon, and Pine Canyon.

Much of the land below the Mogollon Rim lies 4000 to 5000 feet (1,200 to 1,500 m) above sea level, with the escarpment rising to approximately 7000 feet (2,100 m). Extensive Ponderosa Pine forests are found both on the slopes of the Rim and on the plateau above. It is a major floristic and faunal boundary, with the Rocky Mountains flora and fauna on the top of the ridge northward, and the Mexican Sierra Madre Occidental flora and fauna on the lower slopes and the sky island mountains further south.

The Mogollon Rim's limestones and sandstones were formed from sediments deposited in the Carboniferous and Permian periods. Several of the Rim's rock formations are also found in the walls of the Grand Canyon. In many places the Rim is capped or even buried by extensive basaltic lava flows.

Cities near the Mogollon Rim include Sedona, Camp Verde, Payson, and Show Low. The eastern portion of the Rim was the site of Arizona's largest-ever wildfire in June 2002, the 470,000 acre (1,900 km²) Rodeo-Chediski fire. Other large fires have burned along the Rim since 1990, and the area's Ponderosa Pine forests remain vulnerable due to past fire suppression and fuel build-up