Aja is the sixth studio album by the American jazz rock band Steely Dan, released by ABC Records on September 23, 1977. For this album, band leaders Donald Fagen and Walter Becker expanded their experimentation with various session musicians, enlisting nearly 40 players to create more complex compositions and arrangements.
 
The album reached number three on the Billboard Top LPs & Tape chart and number five on the UK Albums Chart, making it Steely Dan's most commercially successful release. It featured hit singles such as "Peg," "Deacon Blues," and "Josie."
 
At the 20th Annual Grammy Awards, Aja won Best Engineered Recording – Non-Classical and received nominations for Album of the Year and Best Pop Performance by a Duo or Group with Vocals. The album is frequently included on "greatest albums" lists, praised by critics and audiophiles for its exceptional production quality. In 2010, the Library of Congress recognized Aja as "culturally, historically, or aesthetically significant," selecting it for preservation in the National Recording Registry.