Buying in Marion County, Illinois

Marion County at a glance

Marion County is one of 102 counties and county-equivalents in Illinois. Its county seat is Salem. County government publishes its offices and parcel tools online. Official county website. Its 2024 Census Bureau population estimate is 36,437 across 572 square miles of land — about 64 people per square mile. In the FBI's 2024 reported-crime file, agencies here reported 640 offenses — 17.56 per 1,000 residents; the breakdown is below.

Records to check before you buy in Marion County

• Property record card — the Marion County assessor / appraisal office. Pull the parcel's assessed-value history, exemption status, and last sale. This is the file your future tax bill is calculated from, and it shows whether the current owner is enjoying exemptions you will not inherit. County government sits in Salem; the official county website is the reliable route to the parcel search and the office directory.
• Deeds & liens — the Marion County recorder / land-records office. Read the deed chain, open liens, easements, and plat maps — the file a listing never mentions.
• Official flood determination. Check the exact parcel on FEMA's National Flood Hazard Layer — not the listing site's licensed model. Zone boundaries cut through streets; the house next door can be in a different zone. Marion County is the primary county for 10 ZIP codes in the Census Bureau's ZIP-to-county crosswalk — and zone lines ignore every one of them.
• The county's reported-crime record. In the FBI's 2024 file, agencies in Marion County reported 640 offenses — 17.56 per 1,000 residents; the largest single category was larceny-theft (289). The crime section below sets that beside the Illinois county median.
• Registry check. Run the address through Illinois State Police Sex Offender Registry (Illinois State Police) and note the counts within a mile — then check again the week you close.
• Permits & code history — the Marion building department. Open permits, expired permits, and code cases tell you whether the renovation in the photos was ever inspected. County permitting is run out of Salem.
• School assignment — the district office, not the listing. Only the district's own boundary lookup confirms which school an address is actually zoned for.

County list, land area and population: U.S. Census Bureau (population: 2024 PEP estimate). County seat and official website: Wikidata (CC0), checked 2026-11-04. Flood determinations: FEMA. Registry: Illinois.

Reported crime in Marion County — FBI 2024

Agencies in Marion County reported 640 offenses to the FBI in 2024 — 139 violent and 501 property offenses. That works out to a reported-crime rate of 17.56 per 1,000 residents (violent 381.5, property 1375.0 per 100,000).

Inside Illinois, the median county in the same file recorded a violent-crime rate of 108 per 100,000 and a property-crime rate of 593 per 100,000 (medians computed from the FBI 2024 county file across 102 counties).

The largest reported categories were larceny-theft (289), burglary (154) and aggravated assault (112).

Coverage: 8 of 8 law-enforcement agencies assigned to this county reported at least one month of 2024 offense data to the FBI; 5 reported all 12 months. Counts are reported offenses only (FBI Return A / Arson master files), assigned whole to each agency's primary county; they are not adjusted for non-reporting agencies.

These are offenses reported to law enforcement — not convictions, and not a verdict on any street or address. A CurbFacts report pairs this county record with the ZIP-level picture for the specific address you are buying.

Source: FBI Crime Data Explorer, UCR Return A + Arson master files, data year 2024 (pulled 2026-11-04).

ZIP guides in Marion County

Registry counts and county crime records for the 10 ZIP codes whose primary county is Marion County.

The Illinois rules that apply in Marion County

Traps researched for Illinois buyers: Exemptions vanish after a sale until you re-apply; Cook County reassesses on a different clock.

Read the full Illinois guide — disclosure standard, tax math, registry and flood

More Illinois counties

All Illinois counties · Illinois buyer guide