Astro Boy (Japanese: 鉄腕アトム, Hepburn: Tetsuwan Atomu, "Mighty Atom", lit. "Iron Arm Atom") is a Japanese television series that premiered on Fuji TV on New Year's Day, 1963 (a Tuesday), and is the first popular animated Japanese television series that embodied the aesthetic that later became familiar worldwide as anime. It originated as a manga of the same name in 1952 by Osamu Tezuka, revered in Japan as the "God of Manga". It lasted for four seasons, with a total of 193 episodes, the final episode presented on a Saturday, New Year's Eve 1966.

At its height it was watched by 40% of the Japanese population who had access to a TV. In 1964, there was a feature-length animated movie called Mighty Atom, the Brave in Space (鉄腕アトム 宇宙の勇者, Tetsuwan Atomu: Uchū no yūsha) released in Japan. It was compiled from three selected episodes from the series—episodes 46 ("The Robot Spaceship"), 56 ("Earth Defense Army") and 71 ("The Last Day of Earth"), respectively. The latter two were filmed and produced in color.

Between 1963 and 1965, 104 episodes were aired in the United States, adapted to the English language. After enjoying success both in Japan and abroad as the first anime to be broadcast overseas, Astro Boy was remade in the 1980s under the name New Mighty Atom and again in 2003 as Astro Boy: Mighty Atom.