Based on Nikolai Gogol's 1836 play, an illiterate vagabond is taken for an inspector general, and his con-man partner tries to work it for money.
A man arrives from another town and warns the Mayor (Gene Lockhart) that the Inspector General is coming. In the street Yakov Goury (Walter Slezak) presents a living head on a platter to sell his elixir. Georgi (Danny Kaye) sings "The Medicine Show." He tells a mother the elixir is no good, is overheard, and has to flee. Georgi and Yakov hide in a river. Yakov tells Georgi to go away, and Georgi keeps part of a letter signed by Napoleon.
Hungry Georgi asks a soldier for food and is treated like a dog. A horse and cart follow him, and Kovatch (Alan Hale) arrests him. The Mayor thinks that Georgi may be the Inspector General in disguise. Georgi demands to be let out of jail, and the Mayor finds the letter. He kisses Georgi and says they will obey. He makes Kovatch give him his uniform and invites Georgi to a feast.
The Mayor's wife Maria (Elsa Lanchester) orders servants and sits by Georgi. Leza (Barbara Bates) spills wine on Georgi, but he excuses her. Georgi eats voraciously and is given Yakov's elixir.
Georgi wakes up in bed. The Mayor has planned inspections and a hanging. People sing "Brodny." Yakov sees Georgi and says he is his assistant. Privately he persuades Georgi to stay so they can get money. Georgi sings "The Inspector General" with three alter egos.
At the town hall Georgi looks in large books. He avoids a soldier he saw before and does acrobatics. Georgi wants to leave, but in the kitchen Leza says how much they need him. Georgi encourages her and sings "Happy Times." Maria shows him a book about imperial officials and offers herself to him. One by one councilors come in, give Georgi a bribe, and hide. When Yakov and the Mayor come in, they are all exposed, and Georgi goes out. Yakov tells the Mayor and Kovatch that they need a church organ, and they realize that he knows their corruption. Leza warns Georgi with a note, but he can't read. Yakov lies and tells Georgi she wants to meet him in the barn at midnight.
Col. Castine (Walter Catlett) arrives, and Yakov smashes his glasses. Georgi sings "The Gypsy Drinking Song" and plays a violin. At midnight Georgi goes to the barn and learns they are trying to kill him. Yakov shows Georgi's head on a platter and offers to get rid of the evidence for money. Maria faints. Georgi fights Yakov and leaves with Leza.
The Inspector General (Rhys Williams) arrives and signs a death warrant for Georgi, who comes back to end corruption. Before their execution Georgi steals the credentials; but he confesses that he can't read and says he did it to get the organ back. The Inspector General says that Georgi is honest. In the final scene Georgi has been made the mayor.
This farce satirizes Russian political corruption in
the 19th century when most people were uneducated and were easily
manipulated by the upper class.