Yellowknife, city (1991 pop. 15,179), capital of the Northwest Territories, Canada, on the north shore of Great Slave Lake, at the mouth of the Yellowknife River. It is the largest city in the Northwest Territories and a supply and transportation center, with an airport, radio and meteorological stations, a post of the Royal Canadian Mounted Police, regional offices of other federal agencies, and activities related to diamond mining and processing. The town was founded (1935) after the discovery of rich deposits of gold. Another mine was discovered in 1944 and a new townsite was established the next year. Yellowknife, named after a Native American tribe, became capital of the Northwest Territories in 1967.