This name has never been overly common in the Christian world, and it is considered typically Jewish. It was however borne by an 11th-century Hungarian king.
As an English Christian name, Isaac was occasionally used during the Middle Ages, though it was more common among Jews. It became more widespread after the Protestant Reformation. Famous bearers include the physicist and mathematician Isaac Newton (1643-1727) and the science-fiction writer Isaac Asimov (1920-1992).
In America, this name received boosts in popularity from main characters in the movies The Jackal (1997) and Leap Year (2010).