Jacqueline Ruth "Jackie" Cain (May 22, 1928 – September 15, 2014) was an American jazz vocalist. She known for being one half of the Jackie and Roy duo with her husband Roy Kral for over fifty years. The group was active from 1946 until Kral's death in 2002. The released a around 35 albums between 1949 and 1999. The group was described as "the most famous vocal duo in jazz history" by Douglas Martin of "The New York Times".