Laguna Niguel is a city in Orange County, California, United States. The name Laguna Niguel is derived from the words "Laguna" and "Niguili". As of the 2020 census, the population was 64,355. Laguna Niguel is located in the San Joaquin Hills in the southeastern corner of Orange County, close to the Pacific Ocean, and borders the cities of Aliso Viejo, Dana Point, Laguna Beach, Laguna Hills, Mission Viejo, and San Juan Capistrano.

Aliso Creek is a 19.8-mile (31.9 km)-long, mostly urban stream in south Orange County, California. Originating in the Cleveland National Forest in the Santa Ana Mountains, it flows generally southwest and empties into the Pacific Ocean at Laguna Beach. The creek's watershed drains 34.9 square miles (90 km2), and it is joined by seven main tributaries. As of 2018, the watershed had a population of 144,000 divided among seven incorporated cities.