High school student Sam Witwicky becomes involved in an ancient intergalactic conflict between two factions of alien robots, the heroic Autobots and the malevolent Decepticons. Unbeknownst to him, Sam possesses a map that could lead to the AllSpark, a powerful artifact that both sides war over, capable of granting unlimited power. The Autobots aim to protect humanity and use the AllSpark to rebuild their home planet, while the Decepticons seek the artifact to conquer the universe. As the robots disguise themselves as common vehicles on Earth, Sam's life changes dramatically when he buys a vintage car that turns out to be an Autobot named Bumblebee.

Sam teams up with Bumblebee and the other Autobots, including their noble leader Optimus Prime, to prevent the Decepticons from reclaiming the AllSpark. Alongside his new high school crush, Mikaela Banes, and with the government agency Sector 7 hot on their heels, Sam is thrust into a battle that spans from his quiet suburban life to the streets of a bustling city. The fate of humanity hangs in the balance as Autobots and Decepticons charge into a war that tests the courage of the unlikely heroes, and the resolve of their newfound allies.