The Torrey Botanical Society is an organization comprised of people interested in plant life, including professional and amateur botanists, students, and others who simply like to enjoy nature in the country. The society, which began informally in the 1860's under the aegis and inspiration of Columbia College Professor John Torrey, is thought to be the oldest botanical society in America. The early members were amateur botanists, students and colleagues of Dr. Torrey, who were interested in collecting and identifying plants. They occasionally met in the evening to discuss their findings. The organization was first named with the appearance of its first publication, Bulletin of the Torrey Botanical Club, in 1870, and was incorporated in 1871.

Today, the objectives of the society are "to promote interest in botany, and to collect and disseminate information on all phases of plant science." These objectives are fulfilled through indoor meetings, outdoor meeting or field trips, and publications. Since the publications have become standard reference materials for botanists, people residing in practically every state and in a number of other countries have become members. Thus, the society has become an international organization and is affiliated with the American Institute of Biological Sciences. It differs from most scientific societies in that it hosts numerous meetings and field trips.