According to sources, Mathew Daddario has no brother as a sibling.
Mathew Quincy Daddario born on October 1, 1987, is an American actor. He is best known for his role as Alec Lightwood on the Freeform television series Shadowhunters (2016 – 2019).
Mathew Daddario was born and raised in New York City, the son Christina Daddario, a lawyer, and Richard Daddario, a prosecutor and former head of NYPD counterterrorism under Mayor Micheal Bloomberg.
His older sister is actress Alexandra Daddario; he also had younger sister, Catherine Daddario.
Daddario’s paternal grandfather was Emilio Q. Daddario, a Democratic representative to the United States House of Representatives for the state of Connecticut from 1959 to 1981.
He is an Italian, English, Irish, Hungarian, and Slovak ancestry. Daddario attended the Collegiate School, before graduating with a degree in economics from Indiana University Bloomington in 2010.