443,380 people (2024 Census estimate, +4.9% since 2020)
516 square miles of land · 860 people per square mile
“Highest” and “lowest” are just order, not grades: a high rank for poverty or hazard losses means more of it. Each figure's source is in its section below.
19 active community water systems list Loudoun County in the area they serve, reporting 424,405 people served in all (a system that crosses county lines counts its whole population).
| LOUDOUN WATER - CENTRAL SYSTEM surface water · local government · VA6107350 | 334,808 served |
| LEESBURG, TOWN OF surface water · local government · VA6107300 | 65,028 served |
| PURCELLVILLE, TOWN OF surface water · local government · VA6107600 | 8,929 served |
| ROUND HILL, TOWN OF groundwater · local government · VA6107650 | 5,055 served |
| LOVETTSVILLE, TOWN OF groundwater · private · VA6107400 | 2,964 served |
| HAMILTON, TOWN OF groundwater · local government · VA6107150 | 2,240 served |
| SELMA ESTATES groundwater (surface-influenced) · local government · VA6107660 | 1,540 served |
| ELYSIAN HEIGHTS groundwater · local government · VA6107555 | 1,061 served |
Source: U.S. EPA Safe Drinking Water Information System (SDWIS), active community systems, . Look up any system's violations and test results with EPA's search using its ID.
About 277 people were held in Loudoun County's jail, in Vera's latest figure (2025). In 2020 it was about 235.
Source: Vera Institute of Justice, Incarceration Trends (built from federal Bureau of Justice Statistics jail surveys). Counties without their own jail, or that share one, may show no figure.
1 school district has its office in Loudoun County. School taxes are usually the largest part of a property tax bill.
Spent $1.9 billion — $1.6 billion to run schools, about $19,934 per student, plus $305.1 million on buildings and equipment. Money in: $1.2 billion local (mostly property tax), $483.8 million state, $61.4 million federal. Long-term debt: $982.1 million.
Source: U.S. Census Bureau, 2023 Annual Survey of School System Finances. Districts are listed by the county of their main office; some serve neighboring counties too.
Source: County Health Rankings & Roadmaps 2025 (University of Wisconsin Population Health Institute), which gathers federal data (CDC, Census, and others); measures cover different recent years. Blank lines aren't reported for small counties.
Overall risk: Relatively Low compared with other U.S. counties. FEMA estimates natural hazards cost Loudoun County about $60.7 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Very High; social vulnerability: Very Low.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
442 bridges in Loudoun County: 232 in good condition, 207 fair, and 3 poor (0.7%). “Poor” means a main part — the deck, the beams, or the supports — is rated 4 or lower on the federal 0–9 scale. It doesn't mean unsafe to drive; unsafe bridges are closed.
| THOMAS AVENUE over SUGARLAND RUN · built 1970 | 1,687 vehicles a day |
| NEW ROAD over BULL RUN · built 1993 | 621 vehicles a day |
| DAVIS COURT over TUSCARORA CREEK · built 1971 | 195 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $183.8 million of work in Loudoun County in fiscal 2025, about $437 per resident — to the county, cities, schools, hospitals, nonprofits and others.
Source: USAspending.gov, grants by place of performance, fiscal 2025 (Oct. 2024 to Sept. 2025). Search it by county to see each award.
From Grants.gov: posted grants listing county governments as eligible, soonest deadline first; research-only and overseas programs left out; list updated 2026-10-13, refreshed weekly. 62 are open in all. Cities, towns, school districts and nonprofits have their own lists there.
General election: Tuesday, November 3, 2026. Early voting: 2026-09-18 to 2026-10-31. Last day to register to vote: 2026-10-23. Mail ballot request deadline: 2026-10-23. Election Day: 2026-11-03.
Source: Virginia Department of Elections: upcoming elections · Virginia Department of Elections: voter FAQ · Virginia Department of Elections: absentee voting
The budget, property tax rates, audits, local officials and offices for Loudoun County come from the county's own records, which we haven't gathered — not gathered, never hidden. See what a full county site looks like, or ask to have Loudoun County built: brayden.ozark@gmail.com.
More of Virginia: the state government and every county in Virginia.
Nearby counties: Clarke County (19 mi) · Jefferson County, WV (20 mi) · Montgomery County, MD (24 mi) · Manassas Park city (24 mi) · Fairfax city (24 mi) · Manassas city (25 mi).