212,954 people (2024 Census estimate, +3.8% since 2020)
762 square miles of land · 279 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.
17 active community water systems list Onslow County in the area they serve, reporting 286,778 people served in all (a system that crosses county lines counts its whole population).
| ONSLOW WTR AND SEWER AUTHORITY groundwater · local government · NC0467035 | 156,755 served |
| JACKSONVILLE CITY OF groundwater · local government · NC0467010 | 49,093 served |
| USMC LEJEUNE--HADNOT POINT groundwater · federal · NC0467041 | 37,500 served |
| USMC LEJEUNE--HOLCOMB BLVD groundwater · federal · NC0467043 | 17,000 served |
| USMC LEJEUNE--NEW RIVER AIR ST groundwater · federal · NC0467042 | 11,500 served |
| USMC LEJEUNE--RIFLE RANGE buys groundwater · federal · NC0467046 | 3,500 served |
| OLD SETTLERS WATER SYSTEM buys groundwater · local government · NC7067008 | 2,677 served |
| NORTHWEST ONSLOW WATER ASSOC groundwater · private · NC0467030 | 2,555 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 362 people were held in Onslow County's jail, in Vera's latest figure (2024), or 248 per 100,000 residents ages 15–64. In 2019 it was about 408.
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 Onslow County. School taxes are usually the largest part of a property tax bill.
Spent $331.8 million — $308.7 million to run schools, about $11,056 per student, plus $13.7 million on buildings and equipment. Money in: $80.1 million local (mostly property tax), $200.4 million state, $65.1 million federal. Long-term debt: $119.6 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 High compared with other U.S. counties. FEMA estimates natural hazards cost Onslow County about $215.7 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Relatively Moderate; social vulnerability: Very Low.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
172 bridges in Onslow County: 96 in good condition, 72 fair, and 4 poor (2.3%). “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.
| US17 over CHANEY CREEK · built 1957 | 20,000 vehicles a day |
| NC24W over NORTHEAST CREEK · built 1942 | 18,250 vehicles a day |
| SR1109 over HARRIS CREEK · built 1962 | 870 vehicles a day |
| SR1333 over WHITE OAK RIVER · built 1967 | 230 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $64.6 million of work in Onslow County in fiscal 2025, about $316 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. Last day to register to vote: 2026-10-09. Early voting: 2026-10-15 to 2026-10-31. Mail ballot request deadline: 2026-10-20. Election Day: 2026-11-03.
Source: NC State Board of Elections: upcoming election · NC State Board of Elections: vote in person · NC State Board of Elections: voter ID
The budget, property tax rates, audits, local officials and offices for Onslow 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 Onslow County built: brayden.ozark@gmail.com.
More of North Carolina: the state government and every county in North Carolina.
Nearby counties: Jones County (20 mi) · Duplin County (27 mi) · Pender County (28 mi) · Lenoir County (34 mi) · Craven County (34 mi) · New Hanover County (45 mi).