Óscar Isaac Hernández Estrada was born in Guatemala City, Guatemala to a Guatemalan mother, María Eugenia Estrada Nicolle, and a Cuban father, Óscar Gonzalo Hernández-Cano, a pulmonologist. He has two siblings, an older sister, climate scientist Nicole Hernandez Hammer, and a younger brother, journalist Mike Hernandez. Isaac's family settled in the U.S. when he was five months old, and he was raised in Miami, Florida. He has described his evangelical Protestant upbringing as "very Christian." He has also said that he has French origins, describing himself as "definitely a big mix of many things" and is considered a notable French Guatemalan.