City of Diamond Bar

Map showing City of Diamond Bar with surrounding cities and communities. Dark green is San Bernardino County.
Cutaway from Map of Los Angeles County.
See also online Map of Los Angeles County with Cities & Communities.

General Law city
Incorporated: May 18, 1989
City Hall: 21825E Copley Dr, Diamond Bar, California 91765
Website: www.diamondbarca.gov
Population (2020 Census): 55,072 (Also see latest State Population Estimates and Earlier decennial Census Counts).
Population Under Age 18 (2020 Census): 18.4%
Population Density (2020 Census): 3,703.6 persons per square mile
Housing Units: 18,819
Persons Per Housing Unit: 2.9
Land Area: 14.87 square miles (38.51 square kilometers)
Water Area: 0.01 square miles (0.01 square kilometers)
Total Area: 14.88 square miles (38.54 square kilometers)
Geographic Coordinates (Latitude/Longitude): 34.001573 -117.817601

• Racial/Ethnic Demographics for Cities & Unincorporated Communities
• Educational Attainment
• Median Household Income

Other City Facts & Statistics

City Government Officials

Named for the branding iron symbol (a diamond over a bar) of rancher Fredrick Lewis.

City in red below. Click on map for more detailed color map of county.