The Exposition Universelle of 1900, better known in English as the 1900 Paris Exposition, was a world's fair held in Paris, France, from 14 April to 12 November 1900, to celebrate the achievements of the past century and to accelerate development into the next. It was held at the esplanade of Les Invalides, the Champ de Mars, the Trocadéro and at the banks of the Seine between them, with an additional section in the Bois de Vincennes, and it was visited by more than 50 million people. Many international congresses and other events were held within the framework of the Exposition, including the 1900 Summer Olympics.

Many technological innovations were displayed at the Fair, including the Grande Roue de Paris ferris wheel, the Rue de l'Avenir moving sidewalk, the first ever regular passenger trolleybus line, escalators, diesel engines, electric cars, dry cell batteries, electric fire engines, talking films, the telegraphone (the first magnetic audio recorder), the galalith and the matryoshka dolls. It also brought international attention to the Art Nouveau style. Additionally, it showcased France as a major colonial power through numerous pavilions built on the hill of the Trocadéro Palace.

Major structures built for the Exposition include the Grand Palais, the Petit Palais, the Pont Alexandre III, the Gare d'Orsay railroad station and the entrances of Paris Métro stations by Hector Guimard; all of them remaining today, including two original entrances by Guimard.