John Connor is a fictional character and the main protagonist of the Terminator science fiction franchise. In a fictional post-apocalyptic future first referred to in The Terminator, powerful, intelligent machines have dedicated themselves to the eradication of humanity, and John Connor is the leader of the human resistance movement known as Tech-Com that opposes them. Skynet, the supercomputer mainframe of the machines, decides that John Connor is the focal point of the rebellion and that his termination would end the opposition. After repeated failures at terminating John during the war, Skynet decides to use a temporal displacement device to send cyborg assassins called Terminators to various points in John Connor's past in an attempt to terminate him before the war ever begins. John Connor is referred to but does not appear in the original film The Terminator (1984); his mother is the primary target. John Connor is portrayed as a pre-teen by Edward Furlong in Terminator 2: Judgment Day (1991), as a teenager by Thomas Dekker in Terminator: The Sarah Connor Chronicles (2008 TV series), as a young adult by Nick Stahl in Terminator 3: Rise of the Machines (2003), and as a man in his early thirties by Christian Bale in Terminator Salvation, (2009). Other actors have portrayed John in minor scenes, such as flashbacks or flashforwards. There are many elements of the Terminator plot line that allude to the fact that John Connor is similar to a Jesus-like messiah. This includes the shared initials JC.

The film is set in 1984. The premise is that a T-800 (Model 101) Terminator is sent back in time to 1:52 am on May 12, 1984 by Skynet, a supercomputer which will destroy civilization and wage war on humanity with an army of highly armed robots in 1997. The Terminator's mission is to kill Sarah Connor knowing that she will give birth to John Connor, the leader of the human resistance in the future war. In response, John Connor of the future sends a soldier, Kyle Reese, to 2:01 am on the same day so that Reese can protect Sarah.

During this time, John is conceived when Reese and Sarah have a single sexual encounter. Reese is later killed during his attempt to obliterate the Terminator, but Sarah Connor manages to destroy the machine in a hydraulic press. The film ends with a pregnant Sarah, setting off to ensure that John is born and will be able to perform his future role. John Connor is not seen in the present day (1984), but he is born after the events depicted in the movie, and is seen only in a flashback to the future era where he is in his 30's/40's. Although John never appears in the present, Reese does relay a message to Sarah from John saying: "Thank you, Sarah, for your courage through the dark years. I can't help you with what you must soon face, except to say that the future is not set. You must be stronger than you imagine you can be. You must survive, or I will never exist."