The American Dahlia Society (ADS) is a nonprofit organization dedicated to promoting the development and appreciation of dahlias through education, research, and support for local dahlia societies. Serving dahlia enthusiasts in the United States, Canada, and internationally, the society connects members with resources for growing, classifying, exhibiting, and learning about these flowers.

The ADS offers guidance on dahlia fundamentals, tubers, cut flowers, garden and container varieties, and species dahlias. Its online classification resources include a guide to dahlia forms and awards, along with information on trial gardens and judging. The society also supports research initiatives, including work on dahlia viruses and the Dahlia Genome Project, and shares articles, videos, books, news, and a newsletter.

For growers and exhibitors, the ADS provides information about national shows, local society reports, bloom awards, photo contests, and new dahlia introductions. It also helps local societies through grants and organizational resources, and offers membership, member-only materials, events, and opportunities to support its work through donations.