The National Audubon Society (Audubon; /ˈɔːdəbɒn/) is an American non-profit environmental organization dedicated to conservation of birds and their habitats. Located in the United States and incorporated in 1905, Audubon is one of the oldest of such organizations in the world. There are completely independent Audubon Societies in the United States, which were founded several years earlier such as the Massachusetts Audubon Society, Indiana Audubon Society, and Connecticut Audubon Society. The societies are named for 19th century naturalist John James Audubon.

The society has nearly 500 local chapters, each of which is an independent 501(c)(3) non-profit organization voluntarily affiliated with the National Audubon Society. They often organize birdwatching field trips and conservation-related activities. It also coordinates the Christmas Bird Count held each December in the U.S., a model of citizen science, in partnership with Cornell Lab of Ornithology, and the Great Backyard Bird Count each February. Together with Cornell University, Audubon created eBird, an online database for bird observation. The National Audubon Society also has many global partners to help birds that migrate beyond the U.S.'s borders, including BirdLife International based in Great Britain, Bird Studies Canada, American Bird Conservancy, and many partners in Latin America and in the Caribbean. Audubon's International Alliances Program (IAP) brings together people throughout the Western Hemisphere to work together to implement conservation solutions at Important Birds Areas (IBAs).

In 1886, Forest and Stream editor George Bird Grinnell was appalled by the negligent mass slaughter of birds that he saw taking place.^{[citation needed]} As a boy, Grinnell had avidly read Ornithological Biography, a work by the bird painter John James Audubon; he also lived in his early years in a development of the former Audubon estate, Audubon Park in upper Manhattan, and attended a school for boys conducted by Lucy Audubon. The Audubon name would become the namesake of the society he founded, and after its failure, that of local, state, and a national organization bearing that name.

In 1890, a Chicago-based Audubon Society was started under the presidency of E. Irene Rood. About 70 persons joined and the Society was incorporated in 1893.

Within a year of Grinnell founding it his early Audubon Society claimed 39,000 members, eventually growing to 48,862. Each member signed a pledge to "not molest birds". Prominent members included jurist Oliver Wendell Holmes Jr., abolitionist minister Henry Ward Beecher, and poet John Greenleaf Whittier. In under a decade this society was discontinued, but the name and plan survived.

Organizations for the protection of birds were not a wholly new idea. Even before Grinnell's Audubon Society was organized, the American Ornithologists' Union, founded in 1883, was aware of the dangers facing many birds in the United States. There were, however, influential ornithologists who defended the collection of birds. In 1902, Charles B. Cory, the president-elect of the AOU refused to attend a meeting of the District of Columbia Audubon Society stating that "I do not protect birds. I kill them."

In 1895, a second iteration of the Audubon Society was created, with an unbroken history that traces to today. Cousins and Boston socialites, Harriet Hemenway and Minna B. Hall, disturbed by the destruction left by plume hunters, organized a series of afternoon teas with other wealthy local women, encouraging them to avoid feathered garments. They also sent literature asking these women to, in Hall's words, "join a society for the protection of birds, especially the egret". Later that same year, they founded the Massachusetts Audubon Society. Over 900 women came together with Hemenway and Hall, and across the country, many others were doing the same. These boycotts were largely successful, and the efforts of the early society members helped bring about the end of the plume trade and assisted in the introduction of early conservation legislation such as the Migratory Bird Treaty Act. In 1896, Pennsylvania created their Audubon Society, and during the next few years, bird lovers in many other states followed suit. St. Louis Audubon Society (SLAS) was established in 1916 as the St Louis Bird Club. In 1944, the Bird Club became the first local Audubon chapter in the United States. The national committee of Audubon societies was organized at a meeting held in Washington, D.C. in 1902. 1905 saw the organization of the National Association of Audubon Societies for the Protection of Wild Birds and Animals; William Dutcher was president, and T. Gilbert Pearson was secretary and financial agent. During this time, Albert Willcox provided financial support, more than $331,072 in 1905 and 1906. At the end of 1906, the Association had an interest-bearing endowment fund of more than $336,000 and an income from other sources of approximately $9,000.

Birds in the United States were threatened by market hunting as well as for the fashion industry. Pressure from shooting enthusiasts was intense. For example, great auks, whose habit of crowding together on rocks and beaches made them especially easy to hunt, had been driven to extinction early in the century. During one week in the spring of 1897, nature author Florence Merriam claimed to have seen 2,600 robins for sale in one market stall in Washington alone. By the start of the 20th century, the sale of bird flesh had never been greater. The second equally great threat to the bird population was the desire for their plumage. In the late 1890s, the American Ornithologists' Union estimated that five million birds were killed annually for the fashion market. In the final quarter of the 19th century, plumes, and even whole birds, decorated the hair, hats, and dresses of women. Poachers killed game warden Guy Bradley on July 8, 1905; poachers killed Game Warden Columbus G. McLeod in November 1908 in Florida and Audubon Society employee Pressly Reeves of South Carolina also in 1908.