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 the sixth of ten major expositions held in the city between 1855 and 1937. 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 fifty million people. Many international congresses and other events were held within the framework of the exposition, including the 1900 Summer Olympics.

A world's fair, also known as a universal exhibition or an expo, is a large global exhibition designed to showcase the achievements of nations. These exhibitions vary in character and are held in different parts of the world at a specific site for a period of time, typically between three and six months.