Alexandra Anna Daddario was born in New York City on March 16, 1986, the eldest child of Christina, a lawyer, and Richard Daddario, a prosecutor and former head of the New York City Police Department counter-terrorism unit under Mayor Michael Bloomberg. She is of Czech, English, Hungarian, Irish, and Italian descent. Her brother, Matthew Daddario, is also an actor, and she has a sister named Catharine. Her paternal grandfather was Emilio Q. Daddario, a Democratic member of the U. S. House of Representatives for Connecticut from 1959 to 1971. Daddario was raised on Manhattan's Upper East Side. She attended Brearley School as well as the Professional Children's School. Daddario said she decided to be an actress at the age of eleven. She attended Marymount Manhattan College. She has studied the Meisner acting technique for years.