John Doggett (b. April 4, 1960) is a fictional character on the TV series The X-Files, played by actor Robert Patrick of Terminator 2 fame. Robert Patrick appeared in the opening credits of Seasons 8 and 9.

Doggett served as a sergeant in the US Marine Corps Amphibious Unit and he played a role in the Multi-National Peacekeeping Force for Lebanon Development. He retired from the Marine Corps with commendations after being wounded in the line of duty.

After gaining a Masters degree in Public Administration from Syracuse University Doggett went on to work for the New York Police Department, eventually becoming a detective in the Fugitive Division's Warrant section. While he was working for the NYPD, his son, Luke Doggett, was abducted and murdered. Doggett teamed up with Special Agent Monica Reyes, who was working out of the New Orleans FBI field office at the time, to search for his son and his son's killer. The killer would not be found until the Season 9 episode, "Release".

After his son's death, Doggett's marriage to Barbara Doggett failed, ending in divorce.

In 1995, Doggett graduated from the FBI Academy and assumed the position of FBI Special Agent in the Criminal Investigations Division. In 2000, Agent Doggett was assigned by Deputy Director Alvin Kersh to head up the manhunt to find Special Agent Fox Mulder in the Season 8 episode, "Within". The manhunt was unsuccessful and Doggett was demoted to work on The X-Files with Special Agent Dana Scully.

Doggett and his new partner, Agent Reyes, took charge of the X-Files after Mulder was fired from the FBI and Scully left active duty to teach at the FBI Academy and to care of her and Mulder's son, William.