Thomas A. Anderson is a fictional character from the movie The Matrix and its sequels The Matrix Reloaded and The Matrix Revolutions. He is sometimes referred to as The One and has powers beyond machines.

Mr. Anderson, who later prefers to go by his hacker alias "Neo", is invited to enter the "real world", where he finds himself as the "chosen one" to save humankind from the kingdom of intelligent machines in the year of 2199 (approximately). The Matrix is an illusory construct of the world of 1999 (similar to Plato's allegory of the cave) developed by the machines to keep the human population docile and under control. Some humans break free and the " Rebels" free them. This is necessary because humans are now used by the machines as their primary energy source, after humanity blocked out the Sun by contaminating the atmosphere.

The character's names are viewed by some to have intentional plot-related meanings; Neo is a prefix meaning new, and is also an anagram of "one". It is also an anagram of "eon". The coming of "the one" marks the end of an eon in the Matrix. The name Anderson literally means "son of man", the preferred self-title of Jesus Christ (the Messiah in Christianity). The name Thomas can be viewed as a reference to Thomas, a disciple of Jesus, who was famous for his doubting. Religion often comes up in The Matrix, not just in names, for dialog and the film's metaphors are all religiously influenced.