James L. Swanson is an American author and historian known for his New York Times best-seller Manhunt: The 12-Day Chase for Lincoln's Killer, which details the biography of John Wilkes Booth and his conspiracy to assassinate President Abraham Lincoln and other cabinet members. This acclaimed work earned him the Edgar Award.

Swanson holds degrees in history from the University of Chicago, where he studied under John Hope Franklin, and in law from the University of California, Los Angeles. He has occupied various government and think-tank roles in Washington, D.C., including positions at the United States Department of Justice. He is a Senior Fellow at the Heritage Foundation and has represented the Koch-affiliated libertarian think tank, the CATO Institute, on C-SPAN.

Swanson serves on the advisory council of the Ford's Theatre Society. Born on Lincoln's birthday, he has been passionate about collecting books, documents, photographs, art, and artifacts related to Abraham Lincoln's life and death since the age of ten.