Brainiac is a fictional character, a supervillain that appears in comic books published by DC Comics. The character first appeared in Action Comics #242 (July 1958), and was created by Otto Binder and Al Plastino.

An extraterrestrial android (in most incarnations), Brainiac is a principal foe of Superman, and is responsible for shrinking and stealing Kandor, the capital city of Superman's home planet Krypton. Due to complex storylines involving time travel, cloning, and revisions of DC's continuity, several variations of Brainiac have appeared. Most incarnations of Brainiac depict him as a green-skinned being in humanoid form. He is bald, except for a set of diodes protruding from his skull.

In Superman #167 (February 1964), it was retconned that Brainiac was a machine created by the Computer Tyrants of Colu as a spy for them to invade other worlds, for which he was given a non-computer appearance. Brainiac's distinctive gridwork of red diodes across his head are also explained. He was created with visible "electric terminals of his sensory 'nerves'" that he cannot function without. Luthor discovers that the Computers could have given him a twelfth-level intellect, but gave him a tenth-level, the same as them, so he would not try to dominate them. Luthor frees Brainiac from a prison on another world and increases his intelligence, however implants a timer that will make Brainiac black out so the computer doesn't betray him, as only Luthor can reset the timer and if Brainiac tries to tamper with it, one touch will cause an explosion. However Brainiac tricks Luthor by making a device that hypnotizes Luthor, who removes the timer and forgets Brainiac is a computer. Explaining the 1961 introduction of Brainiac's descendant Brainiac 5, his biological disguise included an adopted "son", a young Coluan boy who was given the name "Brainiac 2". In the same issue, the letter column contained a "special announcement" explaining that the change in the characterization of Brainiac was being made "in deference" to the "Brainiac Computer Kit", a toy computer created by Edmund Berkeley which predated the creation of the comic book character