Michael DiMartino (left) and Bryan Konietzko, the series' co-creators

Avatar: The Last Airbender was co-created and produced by Michael Dante DiMartino and Bryan Konietzko at Nickelodeon Animation Studios in Burbank, California. Its animation was mostly done by South Korean studios JM Animation, DR Movie, and MOI Animation. According to Konietzko, the series was conceived in early 2001 when he took an old sketch of a balding, middle-aged man and imagined the man as a child. He drew the character herding bison in the sky and showed the sketch to DiMartino, who was watching a documentary about explorers trapped at the South Pole. Konietzko described their early development of the concept; "There's an air guy along with these water people trapped in a snowy wasteland ... and maybe some fire people are pressing down on them". The co-creators successfully pitched the idea to Nickelodeon vice-president and executive producer Eric Coleman two weeks later.

The series was introduced to the public in a teaser reel at Comic-Con 2004, and premiered on February 21, 2005.

In an interview, Konietzko said: "Mike and I were really interested in other epic 'Legends & Lore' properties, like Harry Potter and Lord of the Rings, but we knew that we wanted to take a different approach to that type of genre. Our love for Japanese anime, Hong Kong action and kung fu cinema, yoga, and Eastern philosophies led us to the initial inspiration for Avatar: The Last Airbender."