Black Diamond is a city in King County, Washington, United States. The population was 4,151 at the2010 census.
Black Diamond was officially incorporated on February 19, 1959.Beginning in the 1880s Black Diamond was a rural coal mining area, developed by the Black Diamond Coal Mining Company of California, which owned and operated the mine. The original residents were largely composed of former workers, from the company's previous coal mining operation in Nortonville, California, which primarily sold coal to the thriving new metropolis of San Francisco.The town has been home to many famous residents, including folk musician Brandi Carlile (who grew up a few miles east in Ravensdale). The minor-league baseball star Edo Vanni was born at Black Diamond in 1918. This city was put onto the official maps on February 9, 1954, which is considered its birthdate.