Set in 1905, the sailors of the Russian battleship Potemkin are refusing to eat the meat that was delivered to their ship because it contained maggots. One of the sailors, Vakulinchuk, has been attempting to lead the other sailors in a mutiny against the officers. Giliarovsky, the second in command, summons the men to the quarterdeck and threatens reprisals against them for not eating the meat. When asked if they will eat the meat now, they still say no. Giliarovsky then summons the marines and orders them to shoot the sailors. While Vakulinchuk pleads with the marines not to shoot, the other sailors and marines decide to join Vakulinchuk and the mutiny is on. The sailors and marines attack the officers and begin to throw them overboard, but not before Giliarovsky shoots and kills Vakulinchuk.
That night, the Potemkin sails to the port city of Odessa, which is in the midst of a general strike, and set up Vakulinchuk's body at the port entrance. The next day, the townspeople see the make-shift shrine to the fallen sailor and see the battleship in the harbor flying a red flag, the symbol of the revolution against the Tsarist regime of Russia. This starts a demonstration in the streets, with most of the demonstrators on the city's famous Odessa Steps. The revolution leaders go to the ship asking for help in fighting the Tsar's army, but the sailors refuse because they know that a squadron of the Tsar's navy is coming to take back the ship, and they need to be ready for that potential fight. While the demonstration is continuing, the army arrives and starts marching down the stairs, shooting and killing the demonstrators, which include women, children, and elderly. The sailors retaliate by firing their ship's cannons at the headquarters of the army's commanders.
The next morning, the lookouts spot the squadron approaching and prepare for a battle. They leave the port of Odessa and travel at full speed at the squadron. The sailors arm the cannons and prepare to fight, all the while signaling the ships to not shoot and even join them. Just as it looks like a battle will commence, the other ships signal back that they will not fire on them. The movie ends with the Potemkin sailing past the squadron, essentially winning the battle without having to fire a single shot.