Amateur
- 501
- Southwest Florida Astronomical Society
- Maps, meetings, past events, resources, star party etiquette, and telescope loan program located in Cape Coral.
- 502
- The Brevard Astronomical Society
- Star parties, meetings, presentations, calendar, album, newsletter, and glossary located at Cocoa.
- 503
- The Northeast Florida Astronomical Society
- Located in Jacksonville and serves the Beaches, Orange Park, and Nassau County and provides observing information, forums, calendar, gallery, files, and resources.
- 506
- Astronomical Society of the Desert
- Calendar of events, photos, history lecture meeting schedule, movies, and special events located in Palm Desert.
- 507
- Central Valley Astronomers
- Calendar, newsletter, forum, meetings, star party etiquette, photographs, and club photo located in Fresno.
- 508
- Fremont Peak Observatory Association
- The only California State Parks cooperative association devoted to interpreting astronomy to the public, and includes information and weather reports for visitors. Located in San Juan Bautista.
- 509
- High Desert Astronomical Society
- Information on membership, meetings, activities, equipment, calendar, and includes a gallery and forum. Located at Apple Valley.
- 510
- Kern Astronomical Society
- Newsletter, notes, images, and star party information located in Bakersfield.
- 513
- Mount Diablo Astronomical Society
- Public program, newsletter, meetings, outreach program, gallery, and satellites based in Walnut Creek.
- 514
- Mountain Skies Astronomical Society
- Gift shop, astronomy village, star atlas, calendar of events, news, and basic information located at Lake Arrowhead.
- 515
- Orange County Astronomers
- Located in Costa Mesa and provides calendar, e-zine, resources, and gallery.
- 516
- Peninsula Astronomical Society
- Provides courses, news, evening and solar viewing information, and special viewings located in Los Altos.
- 517
- Polaris Observatory Association
- Provides telescope and camera information, gallery, and astrophotography information.
- 518
- San Diego Astronomy Association
- Outreach, events, resources, merchandise, utilities, and telescope loaner utility page.