The National Speleological Society (NSS) is an organization formed in 1941 to advance the exploration, conservation, study, and understanding of caves in the United States. Originally headquartered in Washington D.C., its current offices are in Huntsville, Alabama. The organization engages in the research and scientific study, restoration, exploration, and protection of caves. It has more than 10,000 members in more than 250 grottos.

Caving, also known as spelunking and potholing, is the recreational pastime of exploring wild cave systems. In contrast, speleology is the scientific study of caves and the cave environment.