Expo '74, officially known as the International Exposition on the Environment, Spokane 1974, was a world's fair held May 4, 1974, to November 3, 1974 in Spokane, Washington in the northwest United States. It was the first environmentally themed world's fair and attended by roughly 5.6 million people. The heart of the fair park grounds was located on Canada Island, Havermale Island, and the adjacent south bank of the Spokane River, comprising present-day Riverfront Park, in the center of the city.

Spokane is the most populous city in and seat of government of Spokane County, Washington, United States. It is in eastern Washington, along the Spokane River, adjacent to the Selkirk Mountains, and west of the Rocky Mountain foothills, 92 miles (148 km) south of the Canadian border, 18 miles (30 km) west of the Washington–Idaho border, and 279 miles (449 km) east of Seattle, along Interstate 90.