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 counterterrorism unit. She is of Italian, Irish, English, and Slovak descent. She has a younger brother, Matthew Daddario, and a younger sister, Catharine Daddario, who are both actors as well. 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 the Brearley School and the Professional Children's School. Daddario said she decided to be an actress at the age of 11. "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." She attended Marymount Manhattan College before dropping out to pursue acting full-time. She has spent years studying the Meisner acting technique. Daddario made her television debut at the age of 15, when she played victimized girl Laurie Lewis in the ABC daytime soap opera All My Children. Her first major role was as Annabeth Chase in the fantasy adventure film Percy Jackson & the Olympians: The Lightning Thief (2010). She also had a recurring role as Neal Caffrey's love interest, Kate Moreau, in the USA Network procedural drama series White Collar. In 2011, she appeared in the film comedy, Hall Pass, and had a recurring role as Rachel in NBC's comedy-drama series, Parenthood.