Coordinates: 33°05′03.15″N 117°01′03.11″W / 33.0842083°N 117.0175306°W San Pasqual Valley is the northernmost community of the city of San Diego. It is named for the Kumeyaay village of San Pasqual that was once located there. It is bordered on the north by the city of Escondido, on the east and west by unincorporated land within San Diego County, and on the south by the city of Poway and the community of Rancho Bernardo. San Pasqual Valley is home to the San Diego Zoo Safari Park.
State Highway 78 runs through the valley between Escondido and Ramona. The valley is part of the Santa Ysabel Creek watershed, which drains into the San Dieguito River.
The wagon road from Warner's Ranch to San Diego passed through San Pasqual Valley on its way between Santa Ysabel Asistencia and Rancho Santa Maria de Los Peñasquitos. In 1846, during the Mexican-American War, this road led to the Battle of San Pasqual being fought in the valley near the site of the Kumeyaay village of San Pasqual. On December 6 and December 7, 1846, the Californios, led by General Don Andrés Pico, fought Stephen W. Kearny's column of 140 U.S. Army troops as they descended from the Santa Maria Valley into the valley near San Pasqual on their way from Warner's Ranch to San Diego. Subsequently, it was the road into San Diego County from the Southern Emigrant Trail.