Steely Dan is an American jazz rock band whose music also blends elements of crossover jazz, latin music, blue-eyed soul, R&B, boogie, and pop. Founded by core members Walter Becker (guitars, backing vocals) and Donald Fagen (keyboards, lead vocals) in 1972, the band enjoyed critical and commercial success starting from the early 1970s until breaking up in 1981. Rolling Stone has called them "the perfect musical antiheroes for the Seventies". Steely Dan reunited in 1993 and has toured steadily ever since.

Recorded with a revolving cast of session musicians, Steely Dan's music is characterized by complex jazz-influenced structures and harmonies. Becker and Fagen are whimsical, often sarcastic lyricists, having written "cerebral, wry and eccentric" songs about recreational drugs, love affairs, gambling, and crime. The pair is also known for their near-obsessive perfectionism in the recording studio: Over the year they took to record Gaucho (1980), an album of just seven songs, Becker and Fagen hired at least 42 studio musicians and 11 engineers.

Steely Dan toured from 1972 to 1974 before retiring from live performances, becoming a studio-only band. After the group disbanded in 1981, Becker and Fagen were less active throughout most of the next decade, though a cult following remained devoted to the group. Since reuniting in 1993 Steely Dan has released two albums of new material, the first of which, Two Against Nature, earned a Grammy Award for Album of the Year. They have sold more than 40 million albums worldwide and were inducted into the Rock and Roll Hall of Fame in March 2001.

Steely Dan was listed as one of the 100 greatest musical artists of all time according to VH1.