John D. Hackensacker III is a fictional character from the 1954 Broadway musical and 1956 film titled Bells Are Ringing. He is portrayed as a wealthy and carefree businessman who becomes romantically involved with the main character, Ella Peterson, a telephone answering service operator. In the story, Hackensacker's charm and affluence contrast with Ella's more modest lifestyle. His character adds a layer of complexity to the narrative, highlighting themes of love, ambition, and the clash between different social classes. The musical showcases their relationship through catchy songs and engaging dialogue.