Lewiston is a city in and also the county seat of Nez Perce County in the state of Idaho. It is the second-largest city in the northern Idaho region, behind Coeur d'Alene and ninth-largest in the state. Lewiston is the principal city of the Lewiston, ID - Clarkston, WA Metropolitan Statistical Area, which includes all of Nez Perce County and Asotin County, Washington. As of the 2010 census, the population of Lewiston was 31,894.

Lewiston is located at the confluence of the Snake River and Clearwater River, thirty miles (50 km) northwest of the Lower Granite Dam. Because of dams (and their locks) on the Snake and Columbia River, Lewiston is reachable by some ocean-going vessels. The Port of Lewiston (Idaho's only seaport) has the distinction of being the farthest inland port east of the West Coast of the United States. The Lewiston-Nez Perce County Airport serves the city by air.

Lewiston was founded in 1861 in the wake of a gold rush which began the previous year near Pierce, northeast of Lewiston. In 1863 Lewiston became the capital of the newly created Idaho Territory. Lewiston's stint as seat of the new territory's government was short-lived as a resolution, to have the capital moved from Lewiston to Boise, was passed by the Idaho Territorial Legislature on December 7, 1864.

Lewiston’s main industries are agriculture, paper and timber products, and light manufacturing. Lewiston is home to Lewis-Clark State College, a public undergraduate college. Cultural activities in Lewiston include the Dogwood Festival, Hot August Nights, and the Lewiston Round Up.