The Seattle Astronomical Society (SAS) is a non-profit organization that has been dedicated to amateur astronomy since its establishment in 1948. Comprised of members of all ages and backgrounds, the SAS fosters a community centered around the observational, educational, and social aspects of astronomy. Their mission is to promote and provide meaningful astronomical activities for SAS members, as well as offer outreach and education for the public.

The society organizes monthly meetings featuring programs and lectures presented by professional scientists and accomplished amateur astronomers, covering a wide range of topics in astronomy. They also host star parties open to the public, allowing enthusiasts to observe celestial objects through telescopes. Furthermore, the SAS engages in various outreach initiatives, such as participating in science night events at local public schools and organizing special observing sessions for significant astronomical events.

With a diverse range of activities and a passion for astronomy, the Seattle Astronomical Society welcomes both novices and experienced astronomers to join their vibrant community