The Orange County Astronomers is a non-profit organization whose main purpose is to spread knowledge and appreciation of the science of astronomy. The club has been doing this for more than 40 years and has grown to over 800 members.

The Columbia Astronomers are the official astronomy club of the Columbia Memorial Space Center. The Columbia Astronomers welcomes people of all ages and skill level. Every month, members are treated to a guest speaker and night sky viewing (weather permitting). Telescopes are made available during each meeting, however, you are encouraged to bring your own telescope as well!

Headquartered in the Inland Valley, the PVAA is a group of about 100 amateur astronomers who enjoy the mystery and beauty of the night sky and wish to share it with each other, local schools, and the community. The club comes together twice every month for scheduled activities.

The Riverside Astronomical Society has a history of civic and educational support since its beginnings in 1957. The RAS owes its start to people who saw the need to promote a better awareness of astronomy to the general public. In addition, they saw a need for a common forum for amateur astronomers to further develop and advance their hobby.