The Sierra de Juárez is a mountain range of the northwestern Baja California Peninsula, located in northern Baja California state, Mexico.
The Sierra de Juárez range is within the Peninsular Ranges System of Southern California and the Baja California Peninsula. The Laguna Mountains (U.S.) are on the north, and the Sierra San Pedro Mártir (México) are on the south, both Peninsular Ranges also.
The range is the location of the southern tip of the Great Basin Divide at a triple watershed point of the Great Basin (northern), the Pacific Ocean (western), and Gulf of California (eastern) watersheds.
The higher elevation Sierra Juarez is protected within Constitution 1857 National Park, approximately 45 miles (72 km) east of Ensenada. The scenic lake Laguna Hanson, an important stopover for migratory birds, and the endemic pine-oak forests habitat are within the park.
The lower elevations of the western Sierra Juarez slopes are within the California coastal sage and chaparral sub−ecoregion of the California chaparral and woodlands ecoregion.