"Deacon Blues" is a song by Walter Becker and Donald Fagen, who wrote the music and lyrics. The American rock band Steely Dan recorded it for their sixth album, Aja (1977), where it closes the record in a version running 7:36. Written in 1976, it is a jazz rock song. Gary Katz produced the recording at Village Recorder in Los Angeles in 1977. Larry Carlton plays the guitar opening, Tom Scott wrote the horn arrangement, and Pete Christlieb takes the tenor saxophone solo. Becker plays bass, the only Aja track where he does.
Released as a single in March 1978 in a 6:33 version, with "Home at Last" on the B-side, the song reached No. 19 on the US Billboard Hot 100, No. 17 on Cash Box and No. 14 in Canada, Steely Dan's fifth Top 20 hit. Aja peaked at No. 3 on the Billboard album chart. Rolling Stone ranked the song No. 214 in its 2021 list of the 500 Greatest Songs of All Time. Fagen has said it is partly autobiographical, and the name comes from football player Deacon Jones. Bill Callahan and Will Oldham recorded a cover in 2020, released on their 2021 album Blind Date Party, and the Scottish band Deacon Blue took its name from the song.