What is Krusty the Clown’s real name?

The answer is: Herschel Shmoikel Pinchas Yerucham Krustofsky. In Season 3 Episode 6, "Like Father, Like Clown", we find out what Krusty’s real name is, as well as learn more about his upbringing on the Lower East Side of Springfield. Despite the fact he was estranged from his father due to his desire to perform comedy, the pair reconcile with the help of Bart and Lisa Simpson.Source