Black Diamond, Washington

Black Diamond, Washington
Top Works at Mine 11, Black Diamond, ca. 1915.
Location of Black Diamond, Washington
Coordinates: 47°18′35″N 122°00′15″W / 47.30972°N 122.00417°W / 47.30972; -122.00417
CountryUnited States
StateWashington
CountyKing
Establishedmid-1880s
IncorporatedFebruary 19, 1959
Government
  TypeMayor–council
  MayorCarol Benson
Area
  Total
7.19 sq mi (18.65 km2)
  Land6.60 sq mi (17.09 km2)
  Water0.60 sq mi (1.54 km2)
Elevation
558 ft (170 m)
Population
 (2020)
  Total
4,697
  Estimate 
(2023)
6,602
  Density1,000.51/sq mi (386.29/km2)
Time zoneUTC–8 (Pacific (PST))
  Summer (DST)UTC–7 (PDT)
ZIP Code
98010
Area code(s)360 and 564
FIPS code53-06330
GNIS feature ID2409855
Websiteblackdiamondwa.gov

Black Diamond is a city in King County, Washington, United States. The population was 4,697 at the 2020 census. In 2023, with a 40.6% growth rate, Black Diamond was the fastest growing small city in King County.