The lycée Saint-Louis is a higher education establishment located in the VIe arrondissement of Paris, in the Latin Quarter. It is the only public French lycée exclusively dedicated to classes préparatoires aux grandes écoles (CPGE, the preparatory classes for the Grandes Écoles). It is known for the quality of its teaching and the results it achieves in their intensely competitive entrance examinations (concours).
History: the Collège d'Harcourt 
Until 1820, the lycée Saint-Louis was named Collège d'Harcourt. At the time of its founding it was meant to be a residence for students of the University of Paris. The latter was founded in 1280 by Robert and Raoul d'Harcourt to offer food and lodgings to some forty impoverished students. It was not originally a teaching establishment, but this became an increasingly important part of its function over the years.
The original building was demolished in 1795 and the present one erected on its site in 1814.
In the course of the 19th century, the lycée was successively a prison, barracks and reformatory.
Famous former pupils 
- Joseph Bertrand, Mathematician, Academician;
- Nicolas Boileau, Writer, Academician;
- Fortuné du Boisgobey, Writer.
- Georges Charpak, Physicist, Nobel Prize 1992;
- Hubert Curien, Physicist, Former Minister of Research;
- Denis Diderot, Writer and Philosopher.
- Charles François Dupuis, author;
- Pierre-Gilles de Gennes, Physicist, Nobel Prize 1991;
- Charles Gounod, Composer;
- André Action Diakité Jackson, Diamantaire;
- Eugène Labiche, Playwright;
- Louis Néel, Physicist, Nobel Prize 1970;
- Louis Pasteur, Biologist, Academician;
- Charles Perrault, Writer, Academician;
- Jean Racine, Dramatist, Academician;
- Alain Robbe-Grillet, Writer and Cinematographer;
- Alexandre Rousselin de Saint-Albin, politician;
- Charles de Saint-Évremond, writer;
- Antoine de Saint-Exupéry, Writer;
- Claude Simon, Writer, Nobel Prize 1985;
- Charles Maurice de Talleyrand-Périgord, Statesman;
- Yves Tanguy, Surrealist Painter;
- René Thom, Mathematician, Fields Medal 1958;
- André Weil, Mathematician;
- Émile Zola, Writer.
- the history is given in H.L. Bouquet, L'anciencollège d'Harcourt et le lycée Saint-Louis, Paris, 1891.
- L'ancien collège d'Harcourt et le lycée Saint-Louis, Bouquet, H.L., Paris, Delalin frères, 1891.
- Du collège d'Harcourt, 1280, au lycée Saint-Louis, 1980, Fusellier, E., Euvrard, M., Paris, A.P.E. du lycée Saint-Louis, 1980.
- Septième centenaire !, Humblot, H., in Bulletin d'information de L'association des parents d'élèves du lycée Saint-Louis. 1978/1979.