Aguanga is a census-designated place located within the Inland Empire, Riverside County, California. It is located 22 miles (35 km) south-southeast of Hemet. Aguanga lies at an elevation of 1955 feet (596 m). As of the 2010 census, it had a population of 1,128.
According to the United States Census Bureau, the CDP covers an area of 13.6 square miles (35.2 km²), all of it land.
The community of Aguanga lies at the intersection of State Route 79 (SR 79) and State Route 371 (Cahuilla Road). This is along the historic Butterfield Overland Mail stage route. The area lies at about 1,940 feet (590 m) above mean sea level (AMSL) and is north of Cleveland National Forest. The straight-line distance to Palomar Observatory is 5.9 miles (9.5 km) south and the observatory site is about 3,500 feet (1,100 m) higher than the community. The town is also home to Cottonwood Elementary School (K-8) operated by the Hemet Valley Unified School District. The largest nearby town is Temecula, (along the Interstate 15 corridor), about 18 miles (29 km) west of Aguanga on SR 79.