Black Mountain is a summit in the Cleveland National Forest of the Peninsular Ranges in eastern San Diego County, California, north of Ramona. The peak is measured at , and is sometimes referenced as Big Black Mountain to distinguish it from the smaller Rancho Peñasquitos Black Mountain Open Space Park in the city of San Diego. Black Mountain offers a WX channel for people who wish to tune in on radios to hear the weather; the channel is located on VHF frequency 162.4000 MHz.
Black Mountain is home to one of the largest remaining tracts of the threatened Engelmann oak (Quercus engelmannii).