Nampa ( ) is the most populous city in Canyon County, Idaho, United States. The population was 100,200 at the 2020 census. It is Idaho's third-most populous city. Nampa is about 20 miles (32 km) west of Boise along Interstate 84, and 6 miles (9.7 km) west of Meridian. It is the second principal city of the Boise metropolitan area. The name "Nampa" may have come from a Shoshoni word meaning 'moccasin' or 'footprint'. According to toponymist William O. Bright, the name comes from the Shoshoni word /nampai/, meaning "foot". The city has a prominent student population, home to the College of Western Idaho and Northwest Nazarene University.