François Merlin (Jean-Paul Belmondo) is a Jean Bruce type writer of pulp espionage novels (he has written 42 so far) and about half of the film plays in his imagination, where he is the world-renowned superspy Bob Sinclar. (The name of the character is never seen written in the film. While some people write his name "Saint-Clair", the way it is pronounced in French sounds like Sinclar; in the English dubbed soundtrack the surname is "St. Cloud".)

Christine (Jacqueline Bisset) is a sociology student who lives in François' building and is interested in the novels, but in the writer's imagination she becomes Tatiana, his paramour, while the pompous and rich publisher of his novels, Pierre Charron (Vittorio Caprioli), doubles as the great villain of the spy novels, the Albanian secret service's head Karpov, who in a memorable scene of the film threatens to cut off one of Tatiana's breasts.

Christine is clearly fascinated with the handsome spy Bob Sinclar, an unrealistic and idealised hero, who is the very opposite of his creator: a clumsy, frustrated divorced man who barely makes enough money to get by. However, when she is befriended by the rich and vain publisher who looks down upon his poor hack writer, she realises her mistake, and after a party where he tries to seduce her, she flees him and falls asleep on the landing outside the writer's flat, where he finds her in the morning, clad apparently only in a T-shirt and embraces her for a happy ending. In the final scene, François throws over the balcony his last manuscript, freeing himself from his character and his imaginary life.

Due to a dispute between Francis Veber and director Philippe de Broca over the importance of the lead female character to the script, Francis Veber refused to be credited as a writer. As a result, the credits don't feature any writer.

In the United Kingdom, Le Magnifique was titled How to Destroy the Reputation of the Greatest Secret Agent, and was released as the B-Movie to the film Doc Savage: The Man of Bronze in 1975.

• Jean-Paul Belmondo : François Merlin / Bob Saint-Clar
• Jacqueline Bisset : Christine / Tatiana
• Vittorio Caprioli : Georges Charron / Colonel Karpof
• Monique Tarbès [fr] : Mrs. Berger
• Mario David (actor) : Policeman
• Raymond Gérôme : General Pontaubert
• Jean Lefebvre : The electrician
• Hans Meyer : Colonel Collins
• André Weber : The plumber
• Hubert Deschamps : Salesman
• Bernard Musson : Interpreter
• Louis Navarre (actor) [fr] : Interpreter
• Jean-Pierre Rambal [fr] : The Lecturer
• Gaëtan Noël [fr] : Doctor

This is the film that is the main inspiration for the three teenage heroes of the novel by Andrei Makine, Once Upon the River Love (Au temps du fleuve Amour, 1994).

French DJ Bob Sinclar took his stage name from the unseen super spy.

• Le Magnifique at IMDb  
• Le Magnifique at Rotten Tomatoes
• Le Magnifique^{[permanent dead link]} at Le Film Guide