Timothy J. McCarthy (born June 20, 1949) is a former United States Secret Service agent who served under five U.S presidents; from Richard Nixon to Bill Clinton. He is best known for his notable act of bravery while defending President Ronald Reagan during the assassination attempt on Reagan's life on Monday, March 30, 1981, in Washington, D.C..

During the assassination attempt, McCarthy spread his stance to protect Reagan as six bullets were being fired by the would-be assassin, John Hinckley, Jr.. McCarthy stepped in front of President Reagan, saving the President from harm at considerable risk to his own life. McCarthy survived a .22-caliber round in the abdomen. 

McCarthy recovered fully and received the NCAA Award of Valor in 1982 for his protection of President Reagan. 

He has served as the current Chief of Police of Orland Park, Illinois since May 1994.