On the Western Front in 1918, a Jewish soldier fighting for the Central Powers nation of Tomainia[8] valiantly saves the life of a wounded pilot, Commander Schultz, who carries valuable documents that could secure a Tomainian victory. However, after running out of fuel, their plane crashes into a tree and the soldier subsequently suffers memory loss. Upon being rescued, Schultz is informed that Tomainia has officially surrendered to the Allied Forces, while the Jewish soldier is carried off to a hospital.
Chaplin as Adenoid HynkelTwenty years later, still suffering from amnesia, the Jewish soldier returns to his previous profession as a barber in a ghetto. The ghetto is now governed by Schultz who has been promoted in the Tomainian regime, now transformed into a dictatorship under the ruthless Adenoid Hynkel.
The barber falls in love with a neighbor, Hannah, and together they try to resist persecution by military forces. The stormtroopers capture the barber and are about to kill him, but Schultz recognizes him and restrains them. By recognizing him, and reminding him of World War I, Schultz helps the barber regain his memory.
Meanwhile, Hynkel tries to finance his ever-growing military forces by borrowing money from a Jewish banker called Hermann Epstein, leading to a temporary ease on the restrictions on the ghetto. However, ultimately the banker refuses to lend him the money. Furious, Hynkel orders a purge of the Jews. Schultz protests against this inhumane policy and is sent to a concentration camp. He escapes and hides in the ghetto with the barber. Schultz tries to persuade the Jewish family to assassinate Hynkel in a suicide attack, but they are dissuaded by Hannah. Troops search the ghetto, arrest Schultz and the barber, and send both to a concentration camp. Hannah and her family flee to freedom at a vineyard in the neighboring country of Osterlich.
Hynkel has a dispute with the dictator of the nation of Bacteria, Benzino Napaloni, over which country should invade Osterlich. The two dictators argue over a treaty to govern the invasion, while dining together at an elaborate buffet, which happens to provide a jar of English mustard. The quarrel becomes heated and descends into a food fight, which is only resolved when both men eat the hot mustard and are shocked into cooperating. After signing the treaty with Napaloni, Hynkel orders the invasion of Osterlich. Hannah and her family are trapped by the invading force and beaten by a squad of arriving soldiers.
Chaplin as Adenoid Hynkel (right) with Jack Oakie as Benzino Napaloni (left)Escaping from the camp in stolen uniforms, Schultz and the barber, dressed as Hynkel, arrive at the Osterlich frontier, where a victory parade crowd is waiting to be addressed by Hynkel. The real Hynkel is mistaken for the barber while out duck hunting in civilian clothes and is knocked out and taken to the camp. Schultz tells the barber to go to the platform and impersonate Hynkel, as the only way to save their lives once they reach Osterlich's capital. The barber has never given a public speech in his life, but he has no other choice. He announces that he (as Hynkel) has had a change of heart, he makes an impassioned speech for brotherhood and goodwill, encouraging soldiers to fight for liberty, and unite the people in the name of democracy.
He then addresses a message of hope to Hannah: "Look up, Hannah. The soul of man has been given wings, and at last he is beginning to fly. He is flying into the rainbow, into the light of hope, into the future, the glorious future that belongs to you, to me, and to all of us." Hannah hears the barber's voice on the radio. She turns toward the rising sunlight, and says to her fellows: "Listen."
