Duarte is a city in the San Gabriel Valley of Los Angeles County, California, United States. As of the 2020 census, the city population was 21,727. Duarte is located on historic U.S. Route 66, which today follows Huntington Drive through the middle of the city. It is bounded to the north by the San Gabriel Mountains, to the north and west by the cities of Bradbury and Monrovia, to the south by the city of Irwindale, and to the east by the cities of Irwindale and Azusa. The town is named after Andrés Avelino Duarte, a Californio ranchero (rancher) who founded the community on his land grant, Rancho Azusa de Duarte.