Air is a Japanese visual novel developed by Key, a brand of Visual Arts. It was released on September 8, 2000 for Windows as an adult game. Key later released versions of Air without the erotic content, and the game was ported to the Dreamcast, PlayStation 2, PlayStation Portable, PlayStation Vita and Nintendo Switch. The story follows the life of Yukito Kunisaki, a traveling showman searching for the "girl in the sky". He arrives in a quiet, seaside town where he meets three girls, one of whom is the key to the end of his journey.

The gameplay in Air follows a branching plot line which offers pre-determined scenarios with courses of interaction, and focuses on the appeal of the three female main characters by the player character. The game is divided into three segments—Dream, Summer, and Air—which serve as different phases in the overall story. The title of the game reflects the prominent themes of the air, skies, and use of wings throughout gameplay. The game ranked as the best-selling PC game sold in Japan for the time of its release, and charted in the national top 50 several more times afterwards. Air has sold over 300,000 units across several platforms.

Following the game's release, Air made several transitions into other media. A manga by Yukimaru Katsura was serialized in Kadokawa Shoten's Comptiq, and later published into two volumes. Comic anthologies and art books were also published, as were audio dramas and several albums of music. Kyoto Animation produced a 13-episode anime television series and a two-episode anime mini-series in 2005, and Toei Animation produced an anime film in 2005. The anime adaptations are licensed by Funimation who released them in North America.