HemisFair '68 was the official 1968 World's Fair held in San Antonio, Texas, from April 6 through October 6, 1968. Local businessman and civic leader, Jerome K. Harris Sr., coined the name HemisFair and conceived the idea for the fair, hoping it would unite all the cultures that comprise San Antonio and solidify the city's reputation as a cultural and historic destination. With help from commissioner Henry B. Gonzales and other San Antonio leaders, the fair materialized and helped transform the city from a cowtown to one of the largest cities in the country. The theme of the fair was "The Confluence of Civilizations in the Americas", celebrating the many nations which settled the region. The fair was held in 1968 to coincide with the 250th anniversary of the founding of San Antonio in 1718. More than thirty nations and fifteen corporations hosted pavilions at the fair.

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.