Louisville Lou (That Vampin' Lady) is the title of a popular song by American composer Milton Ager with lyrics by Jack Yellen. Written in 1923, it is an example of the Tin Pan Alley "vamp" style of music. Also known and listed with ASCAP under the titles of "Stay Away From Louisville Lou" or simply "Louisville Lou", the song tells in lighthearted fashion the tale of the "scandalous vamp" Louisville Lou, "the most heart-breakin'est, shimmy shakin'est that the world ever knew."