Azusa is a city in Los Angeles County, California, United States. It is located in the San Gabriel Valley, at the foot of the San Gabriel Mountains. The area now known as Azusa was originally inhabited by the Asuksa-nga American Indian tribe. The first recorded European to visit the area was Gaspar de Portolà, who led the first Spanish land exploration of Alta California in 1769.

In the early 20th century, Azusa became a hub for the railroad industry, with the San Gabriel Valley Railroad and the Pacific Electric Railway both running through the city. This helped Azusa become a bedroom community for Los Angeles, as many people commuted to work in the city from Azusa.

Today, Azusa is a diverse and thriving community, with a population of over 50,000 people. It is home to Azusa Pacific University, a private Christian university, and Citrus College, a community college. Azusa is also known for its recreational opportunities, with the San Gabriel Mountains and the Angeles National Forest providing a backdrop for outdoor activities such as hiking and mountain biking.