American Jewish songwriting duo.
Bert Kalmar hired Harry Ruby as a song plugger, and as a result of a knee injury that stopped him from dancing professionally, turned to writing songs full-time. Ruby, who had gotten a job at the firm of Waterson, Berlin and Snyder, got Kalmar a job at the same firm writing song lyrics. Before World War I he had begun to write lyrics for a number of different composers. One of them, Ruby, who had also had a number of collaborators, saw a strong compatibility between the two, and by 1920, Kalmar and Ruby recognized that they should form a permanent songwriting team. They also wrote comedy for stage and screen for Wheeler & Woolsey, Eddie Cantor and the Marx Brothers.

Kalmar and Ruby charted forty-six times, with twenty-four of those songs top 10 songs, and forty-two top 20 songs. Together, Kalmar and Ruby formed a successful team until Kalmar’s death in 1947. This partnership is portrayed in the 1950 Metro-Goldwyn-Mayer musical Three Little Words starring Fred Astaire and Red Skelton.