Benny was born in Chicago, Illinois, and grew up in nearby Waukegan, Illinois. He was the son of Meyer Kubelsky and Emma Sachs Kubelsky. His parents were Jewish. Meyer was a saloon owner and later a haberdasher who had emigrated to America from Poland.
Characters
Benny's comic persona changed over the course of his career. At some point he developed a miserly persona. This stage character was everything that Jack Benny was not: cheap, petty, vain and self-congratulatory. His comic rendering of these traits was the linchpin to the success of his show. Benny set himself up as comedic foil, allowing his supporting characters to draw laughs at the expense of his own flaws. With his humanism and vulnerability in an era where few male characters were allowed such character traits, Benny made what could have been unlikable into an everyman character.  Benny said: "I don't care who gets the laughs on my show, as long as the show is funny." Benny felt he got the credit or blame either way, not the actor saying the lines, so there was emphasis on the comedic bottom line. This attitude reached its apogee in a broadcast structured as a Hollywood bus tour of the stars' homes. Each "stop" on the tour was at a house belonging to one of the show's supporting cast, who would then have a scene which included jokes about the absent Benny. Not until the final moments of the program did the bus arrive at Jack Benny's house, at which point the listening audience heard Benny's only line of the episode: "Driver, here's where I get off." Few stars possessed the combination of daring, humility and comic timing to commit to such an extended payoff.  Mary Livingstone, his wife, was a supporting character, as his wisecracking and not especially deferential female friend. She was not quite his girlfriend, since Benny would often try to date movie stars like Barbara Stanwyck, and occasionally had stage girlfriends, such as "Gladys Zybisco". Don Wilson, the rotund announcer, also appeared on the show. He also announced for Fanny Brice's hit Baby Snooks. Bandleader Phil Harris appeared as a jive talking, alcoholic philanderer whose repartee was profoundly risque for its time. Boy tenor Dennis Day appeared as a sheltered, naive youth who often got the better of his boss. This character was originated by Kenny Baker whom Day replaced. Singer Larry Stevens replaced Dennis Day from November 5, 1944 to March 10, 1946, while the latter served in the Navy.

Q: What can you tell me about Jack's characters?
A: Benny's comic persona changed over the course of his career. At some point he developed a miserly persona.

Q: what other Persona did he have?
A: This stage character was everything that Jack Benny was not: cheap, petty, vain and self-congratulatory.
Did he like the characters that he played?
Benny said: "I don't care who gets the laughs on my show, as long as the show is funny."
Benny said: "I don't care who gets the laughs on my show, as long as the show is funny."