Waimea is a landlocked census-designated place (CDP) in Hawaii County, Hawaii, United States. The population was 7,028 at the 2000 census and 9,212 at the 2010 census. Since each U.S. state cannot have more than one post office of the same name, and there is a post office in Waimea, Kauai County, the official U.S. Post Office designation for Waimea is Kamuela, although this name is only used by the post office, not by locals or the local government. The name Waimea means reddish water.

Hawaii County is a county in the U.S. state of Hawaii in the Hawaiian Islands. It is coextensive with the Island of Hawaii, often called the "Big Island" to distinguish it from the state as a whole. The 2020 Census population was 200,629. The county seat is Hilo. There are no incorporated cities in Hawaii County. The Hilo Micropolitan Statistical Area includes all of Hawaii County. Hawaii County has a mayor–council form of government. In terms of geography, Hawaii County is the most expansive county in the state and the most southerly county in the United States.