The T-1000 is a fictional character in the Terminator franchise. A shapeshifting android Terminator assassin, the T-1000 is the main antagonist of Terminator 2: Judgment Day, as well as an antagonist in Terminator Genisys and the theme park attraction T2 3-D: Battle Across Time. A similar Terminator, referred to as a T-1001, appears in the Fox television series, Terminator: The Sarah Connor Chronicles.

In the Terminator franchise, a Terminator is an autonomous cyborg, typically humanoid, conceived as a virtually indestructible soldier, infiltrator, and assassin. A variety of models appear throughout the franchise. Within the fictional storyline, Terminators are created in a post-apocalyptic future by a computer AI known as Skynet, after it has launched war on humans. The machines are created to aid Skynet in its quest, and most are designed as infiltrators with a human appearance. Several Terminators throughout the franchise are reprogrammed by the human resistance to instead serve as protectors.