Ian Caldwell is an American novelist. After graduating from Princeton University in 1998, he and his childhood friend Dustin Thomason co-wrote the semi-autobiographical The Rule of Four, which was published in 2004.
Caldwell and Thomason graduated from the Thomas Jefferson High School for Science and Technology, in Fairfax County, Virginia, in 1994. Caldwell was a Phi Beta Kappa in history at Princeton. In 2005, Caldwell's wife, Meredith, gave birth to their first child, Ethan Sawyer Caldwell. They live in Vienna, Virginia.