Optimus Prime is a character in the Transformers universe. He is the commander of the Autobots, a faction of heroic Transformers from the planet Cybertron who wage their battles to destroy the evil forces of the Decepticons for control of their homeworld, and by extension, peace in the universe. Optimus Prime is depicted as a heroic, brave and compassionate character who puts all his talent to use to improve the world around him. Optimus has a strong sense of justice and righteousness, and has dedicated himself to the protection of all life, particularly the inhabitants of Earth; he will battle his foes with unyielding resolve to uphold this belief.

The original Optimus Prime transforms into a cab over semi truck. The truck's cab transforms into the robot mode of Prime himself, with vast strength and armed with a laser rifle. Contained within his chest is the mystic talisman known as the Autobot Matrix of Leadership (or Creation Matrix), carried by all Autobot leaders and passed down through the ages. The truck's trailer disconnects and transforms into the Combat Deck, a mobile battle-station/command headquarters with an "Auto-Launcher" robot armed with assorted artillery and beam weapons. It can also serve as a radio antenna for battlefield communications between the Autobots. The Combat Deck can launch Prime's third component, Roller, a mobile scout buggy that can easily slip behind enemy lines; when Roller is present somewhere, it is as if Prime is there himself. Injury to one component is felt by each of the others, and while Prime could survive the destruction of either, despite the slight degree of autonomy they possess, the Combat Deck and Roller would not be able to survive without him.

Additional powers included (somewhat inconsistently) in the animated series and comics are short-range optic blasts, holographic map projections, and deployable hydro-foils designed by Wheeljack which allowed Prime and the other Autobots to traverse bodies of water with ease. One of Prime's more memorable abilities from the animated series was the ability to retract his right hand and replace it with a glowing energon axe; although used only once, the axe proved popular enough to be rendered in toy form several times in recent years, and made further appearances in both the Dreamwave Productions and the Devil's Due Publishing comic series.