James Tiberius "Jim" Kirk is a fictional character in the Star Trek franchise. Kirk first appears in Star Trek: The Original Series and has been portrayed in numerous films, books, comics, webisodes, and video games. As the captain of the starship USS Enterprise, Kirk leads his crew as they explore "new worlds, where no man has gone before". Often, the characters of Spock and Leonard McCoy act as his logical and emotional sounding boards, respectively.

Kirk, played by William Shatner, first appears in the broadcast pilot episode, "The Man Trap", originally broadcast on September 8, 1966. Shatner continued in the role for the show's three seasons, and later provided the voice of the animated version of Kirk in Star Trek: The Animated Series (1973–74). Shatner returned to the role for Star Trek: The Motion Picture (1979) and in six subsequent films. Chris Pine portrays a young version of the character in the 2009 reboot Star Trek film, with Jimmy Bennett playing Kirk as a child. Pine reprised his role in Star Trek Into Darkness (2013) and in Star Trek Beyond (2016). Other actors have played the character in fan-created media, and the character has been the subject of multiple spoofs and satires. Kirk has been praised for his leadership traits and criticized for his relationships with women.