Caleb Carr is an American novelist and military historian. He has worked at the Council on Foreign Relations, Foreign Affairs Quarterly, MHQ: The Quarterly Journal of Military History, and taught military history, including World Military History, the History of American Intelligence, and Insurgency/Counterinsurgency, at Bard College.

He was born in Manhattan, and for the majority of his life he lived on the Lower East Side of that city, spending his summers and many weekends at his family's home in Cherry Plain, New York. In 2000, he purchased his own property, known as Misery Mountain, in Cherry Plain; and in 2006 he moved there permanently.

He was educated at St. Luke's School and Friends Seminary in New York, Kenyon College, and New York University, where he gained a degree in Military and Diplomatic History.

He is the author of ten books, several of which, most notably the historical thriller The Alienist, have become international best-sellers and prize-winners, and his work has been translated into over two dozen languages. His book, The Lessons of Terror, concerned one of his non-fiction areas of specialization, terrorism, and became a controversial yet standard volume in the literature of that subject.

He has appeared before the House Joint Subcommittee on National Security, was a featured speaker at a closed-door Defense Department conference on the War on Terrorism, and made regular appearances on almost all television networks during the American invasion of Iraq.

Asked what fiction writers have influenced him the most, he includes Edgar Allan Poe, Wilkie Collins, Charles Dickens, Jules Verne, Rudyard Kipling, William Gibson, and Michael Crichton.

His non-fiction influences he cites as "eclectic and too numerous to list."

Carr has also worked extensively in the theater, and in movies and televison; in the latter capacity, he spent several years in Los Angeles; his last feature script attracted Liam Neeson, John Frankenheimer, and Vittorio Storaro to sign on; when Frankenheimer suddenly and tragically died, however, the project fell apart, and Carr returned to New York.

In 2015, Paramount Television announced that it would create a series based on The Alienist for Turner Network Television (TNT), the first season to be directed by Cary Fukunaga.

He now lives with his Siberian cat, Masha. She is, he says, "very beautiful and very ferocious."