COUNTY · VA
King William County, Virginia
King William County is a county in Virginia with FIPS code 51101 and an estimated population of 19,030 (Census 2023), 82nd largest of 133 in the state.
County facts
- Name
- King William County
- State
- Virginia
- Type
- county
- FIPS code
- 51101
- State FIPS
- 51
- Population (2023)
- 19,030
- Change since 2020
- +6.2%
- State rank
- 82 of 133
Population is the Census Bureau’s Vintage 2023 estimate.
Questions
What is the FIPS code for King William County?
King William County, Virginia has the five-digit FIPS code 51101: 51 for the state and 101 for the county.
What state is King William County in?
King William County is in Virginia.
How do I know if an address is in this county?
Use the address lookup. ZIP codes and city names can cross county lines, so an address is the reliable check.
Sources: U.S. Census Bureau geographic reference files; Census Bureau Population Estimates, Vintage 2023. Last reviewed 2026-10-27.