Trianon may refer to:
- Le Grand Trianon, a palace near Versailles, France
- Le Petit Trianon, a château near Versailles, France
- Le Trianon (theatre), a theatre and concert hall at 80, boulevard de Rochechouart in Paris
- Treaty of Trianon, 1920 post-World War I treaty between Allies and Hungary, defining its borders
- Trianon (Frankfurt am Main), a skyscraper in Germany
- Hotel Trianon, fictional hotel in Graham Greene's 1966 novel The Comedians
- The Trianon, formerly "Claremont," 1907 mansion now the main building of The Colorado Springs School
- "Trianon", the codename of the CIA spy in the 1984 Soviet film TASS Is Authorized to Declare...
- Parque Trianon, a Park in centre São Paulo
- Trianon Ballrooms, Ballrooms during America's bigband era
- Sulfapyridine, by the trade name Trianon