Kamiah is a city in Lewis and Idaho counties in the U.S. state of Idaho. The largest city in Lewis County, it extends only a small distance into Idaho County, south of Lawyer Creek. The population was 1,295 at the 2010 census, up from 1,160 in 2000. The city lies in the narrow valley of the Clearwater River; downstream are Orofino and Lewiston, at the confluence with the Snake River.

Lewis County is a county located in the north central region of the U.S. state of Idaho. As of the 2020 census, the population was 3,533, making it the fourth-least populous county in Idaho. The county seat is Nezperce, and Kamiah is the largest city. Partitioned from Nez Perce County and established in 1911, it was named after the explorer Meriwether Lewis. Most of the county is within the Nez Perce Indian Reservation, though Native Americans comprise less than 6% of the county population. Similar to the opening of lands in Oklahoma, the U.S. government opened the reservation for white settlement in November 1895. The proclamation had been signed less than two weeks earlier by President Cleveland.