Avatar: The Last Airbender (also known as Avatar: The Legend of Aang in several countries) is an award-winning American animated television series that currently airs on the Nickelodeon television network.

Set in an Asian-influenced world of martial arts and elemental manipulation, the series follows the adventures of the latest of a long line of Avatars, Aang, and his friends in a quest to save the world from the ruthless Fire Nation. The series is shown as a book series, with each episode serving as a "chapter" and each individual season as a "book."

Originally slated to begin airing November 2004, Avatar: The Last Airbender debuted on TV on February 21, 2005. The show is also available on DVD or for download at the iTunes Store and Xbox Live Marketplace. Michael Dante DiMartino and Bryan Konietzko are the creators and executive producers of the series along with Aaron Ehasz. The show receives high ratings in the Nicktoons lineup, even outside its intended 6-to-11-year-old demographic. Avatar: The Last Airbender is popular with both audiences and critics, garnering 4.4 million viewers on its best-rated showing.

The series' success prompted Nickelodeon to order second and third seasons. Merchandise based on the series includes eleven DVD sets of episodes, six-inch (15.34 cm) scale action figures, a trading card game, two video games based on the first and second seasons, stuffed animals distributed by Paramount Parks, and two Lego sets.

Avatar draws on four classical elements for its bending arts (rather than the 5 Classical Chinese Elements): Water, Earth, Fire and Air. Although each has its own variation, most ancient philosophies incorporate these four elements in some way, including the classical Hindu, Buddhist, Greek and Japanese elemental traditions.