"Is You Is or Is You Ain't My Baby" is a Louis Jordan song, recorded on October 4, 1943, and released as the B-side of a single with "G.I. Jive". The song reached No. 1 on the US folk/country charts, number two for three weeks on the pop chart, and number three on the R&B chart.
In the 1932 American film Harlem Is Heaven, dancer Bill "Bojangles" Robinson, accompanied by jazz pianist Putney Dandridge, sings "Is You Is or Is You Ain't." The song in the film has different lyrics; but, in addition to its title, its melody is at times similar to that later used for "Is You Is or Is You Ain't My Baby."