Alexandra Anna Daddario was born in New York City on March 16, 1986,[2][3][4] the eldest child of Christina, a lawyer, and Richard Daddario, a prosecutor and former head of the New York City Police Department counterterrorism unit.[5] She is of Italian, Irish, English and Slovak descent.[6] She has a younger brother, Matthew Daddario,[7][8] and a younger sister, Catharine, who are both actors as well.[9] Her paternal grandfather was Emilio Q. Daddario, a Democratic member of the U.S. House of Representatives for Connecticut from 1959 to 1971.[10] Daddario was raised on Manhattan's Upper East Side. She attended Brearley School and the Professional Children's School.[11] Daddario said she decided to be an actress at the age of 11.[12] "I always loved storytelling," she stated in 2019. "It was just something I genuinely wanted to do – and I could've done anything, really. I did have every opportunity on the planet."[13] She attended Marymount Manhattan College before dropping out to pursue acting full-time.[14] She has spent years studying the Meisner acting technique.[15]