Brian Randolph Greene is an American physicist renowned for his revolutionary work in string theory. Born on February 9, 1963, he serves as a professor of physics and mathematics at Columbia University, where he is also the director of the Center for Theoretical Physics. In 2008, he co-founded the World Science Festival and has been its chairman ever since.

Greene is celebrated for his role in the discovery of mirror symmetry and the description of the flop transition and conifold transition, which illustrate changes in spatial topology in string theory. His bestselling books, such as The Elegant Universe, The Fabric of the Cosmos, The Hidden Reality, and Until the End of Time, have been highly influential, making the New York Times bestseller list numerous times.

Beyond his writing, Greene has hosted two Emmy and Peabody Award-winning NOVA miniseries based on his books. His engaging television presence extended to shows like The Big Bang Theory and films such as Frequency and The Last Mimzy. Recognized for his ability to make complex concepts accessible, The Washington Post has deemed him "the single best explainer of abstruse concepts in the world today."