National Geographic (formerly The National Geographic Magazine, sometimes branded as Nat Geo) is an American monthly magazine published by National Geographic Partners. The magazine was founded in 1888 as a scholarly journal, nine months after the establishment of the society, but is now a popular magazine. In 1905, it began including pictures, a style for which it became well known. Its first color photos appeared in the 1910s. During the Cold War, the magazine committed itself to present a balanced view of the physical and human geography of countries beyond the Iron Curtain. Later, the magazine became outspoken on environmental issues.

Until 2015, the magazine was completely owned and managed by the National Geographic Society. Since 2015, controlling interest has been held by National Geographic Partners. Topics of features generally concern geography, history, nature, science, and world culture. The magazine is well known for its distinctive appearance: a thick square-bound glossy format with a yellow rectangular border. Map supplements from National Geographic Maps are included with subscriptions, and it is available in a traditional printed edition and an interactive online edition.

As of 1995^[update], the magazine was circulated worldwide in nearly forty local-language editions and had a global circulation of at least 6.5 million per month including 3.5 million within the U.S., down from about 12 million in the late 1980s. As of 2015^[update], the magazine had won 25 National Magazine Awards. In 2023, National Geographic laid off all staff writers and announced they would stop U.S. newsstand sales in the next year. As of November 2024^[update], its Instagram page has 280 million followers, the third most of any account not belonging to an individual celebrity. The magazine's combined U.S. and international circulation as of June 30, 2024, was about 1.65 million, with its kids magazines separately achieving a circulation of about 500,000.

The first issue of the National Geographic Magazine was published on September 22, 1888, eight months after the Society was founded. In the first issue, Gardiner Greene Hubbard writes,

The "National Geographic Society" has been organized to "increase and defuse geographic knowledge", and the publication of a Magazine has been determined upon as one means accomplishing these purposes.

It was initially a scholarly journal sent to 165 charter members; in 2010, it reached the hands of 40 million people each month. Starting with its January 1905 publication of several full-page pictures of Tibet in 1900–01, the magazine began to transition from being a text-oriented publication to featuring extensive pictorial content. By 1908 more than half of the magazine's pages were photographs. The June 1985 cover portrait of a 12-year-old Afghan girl Sharbat Gula, shot by photographer Steve McCurry, became one of the magazine's most recognizable images.

National Geographic Kids, the children's version of the magazine, was launched in 1975 under the name National Geographic World.

At its peak in the late 1980s, the magazine had 12 million subscribers in the United States, and millions more outside of the U.S.