"Juke" is a harmonica instrumental recorded by the Chicago bluesman Little Walter Jacobs in 1952. Although Little Walter had been recording sporadically for small Chicago labels over the previous five years, and had appeared on Muddy Waters' records for Chess Records since 1950, "Juke" was Little Walter's first hit, and it was the most important of his career. Due to the influence of Little Walter on blues harmonica, "Juke" is now considered a blues harmonica standard.

Marion Walter Jacobs, known as Little Walter, was an American blues musician, singer, and songwriter, whose revolutionary approach to the harmonica had a strong impact on succeeding generations, earning him comparisons to such seminal artists as Django Reinhardt, Charlie Parker and Jimi Hendrix. His virtuosity and musical innovations fundamentally altered many listeners' expectations of what was possible on blues harmonica. He was inducted into The Rock and Roll Hall of Fame in 2008, the first and, to date, only artist to be inducted specifically as a harmonica player.