The Flagg Mineral Foundation is an Arizona-based nonprofit organization dedicated to promoting public interest in earth science and mineral collecting. Founded in 1962 to establish a mineral museum in the Phoenix area, the Foundation built a substantial collection that was once displayed in downtown Phoenix. Although the museum closed in 2011, the organization continues to support museums throughout Arizona and maintains a collection of more than 800 mineral specimens.

With approximately 400 members across several states, the Foundation offers opportunities to learn, connect, and explore. Its activities include organizing the annual A. L. Flagg Gem and Mineral Show and the Minerals of Arizona Symposium, as well as arranging local field trips. The organization also shares information about minerals, its collection, upcoming events, and membership through its website and Facebook page. Named in memory of Arthur L. Flagg, a longtime Arizona mining, geology, and mineralogy enthusiast, the Foundation carries forward his commitment to mineral education and collecting.