Santiago Peak, Mountain summit in Cleveland National Forest, California.

Santiago Peak is a mountain summit in Cleveland National Forest with an elevation of 1,734 meters (5,690 feet), forming the southern portion of the Saddleback formation between Orange County and Riverside County. The peak sits within the Santa Ana Mountains and stands out visibly from the surrounding valleys and plains.

The Acjachemen called the peak Kalawpa, and the nearby village name Alume meant "to raise the head in looking upward," referring to the mountain. The peak is named for Santiago Creek, which begins on its southwestern slope and was itself named after Saint James. In September 2024, the Airport Fire, which started in Trabuco Canyon, burned to the summit and damaged parts of the radio infrastructure.

The name Santiago comes from Santiago Creek, which rises on the peak's southwestern slope and was itself named for Saint James. The Acjachemen call the mountain Kalawpa, and their nearby village name Alume means "to raise the head in looking upward," a reference to the mountain.

The Holy Jim Trail is the most popular route to the summit: a 16-mile (26 km) round trip gaining about 4,000 feet (1,200 m), rated moderate to strenuous. Spring and winter are the better seasons, since insects are numerous in warmer months. At the top, antennas block a full panorama, so walk roughly a quarter-mile around their perimeter to see every direction.

Multiple telecommunications towers crown the summit, enabling radio coverage across several counties for commercial and governmental purposes. This technological infrastructure is visible from the peak and supports the region's modern connectivity.