Mark K. Updegrove is an author, historian, and the CEO of the Lyndon B. Johnson Foundation, a nonprofit organization that supports the LBJ Presidential Library and the LBJ School of Public Affairs at the University of Texas at Austin.

Updegrove served as inaugural CEO of the National Medal of Honor Museum, to be built along the Charleston harbor in Mt. Pleasant, South Carolina. He previously served as the director of the LBJ Presidential Library from 2009 through February 2017.

Updegrove is the author most recently of The Last Republicans: Inside the Extraordinary Relationship Between George H. W. Bush and George W. Bush, (Harper 2017). His other works include Second Acts: Presidential Lives and Legacies After the White House (2006); Baptism by Fire: Eight Presidents Who Took Office During Times of Crisis (2009); Indomitable Will: LBJ in the Presidency (2012); and Destiny of Democracy: the Civil Rights Summit at the LBJ Presidential Library (2015).
He has written for The New York Times, American Heritage, The Nation, National Geographic, Parade, Politico, Texas Monthly, The Daily Beast, and Time. He is an analyst for ABC News on matters relating to the presidency.