Ionia County area

Population and density of Ionia County

The Census Bureau estimates that 66,557 people lived in Ionia County on July 1, 2025. That ranks #835 of 3,222 county equivalents nationally and #30 of 83 in Michigan. Since the April 1, 2020 estimates base of 66,798, the population has declined by 241 (−0.4%), compared with +0.5% for Michigan as a whole.

With 571.3 square miles of land, that is 116 people per square mile (45 per km²), placing Ionia County #897 nationally for density and #29 in Michigan. The median county equivalent has 47 people per square mile; the Michigan median is 62. Put another way, there are about 5.5 acres of land per resident.

U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.

Cities and towns in Ionia County

Ionia County is divided into 19 municipalities and townships. In Michigan, county subdivisions are local governments, and together they cover all of the county’s land and residents.

The most populous is Ionia city, with 12,208 residents (18.3% of the county). The largest by land is Berlin township, at 41.2 mi², or 7.2% of the county’s land. Among those with at least 1,000 residents in 2020, Orleans township grew fastest since then (+3.5%).

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Ionia County. Land: 2026 Census Gazetteer. How communities are listed.

Metropolitan area

Ionia County is an outlying county of the Grand Rapids-Wyoming-Kentwood, MI Metropolitan Statistical Area. Its 5 county equivalents have 1,183,645 residents on 3,242.8 square miles of land; Ionia County accounts for 17.6% of the land and 5.6% of the residents. By combined land it ranks #93 of 393 metropolitan areas, and #50 by population. It belongs to the Grand Rapids-Wyoming, MI Combined Statistical Area.

ZIP codes

21 ZIP Code Tabulation Areas have land in Ionia County; 11 of them have most of their land inside the county, and the others mainly cover neighboring areas.

488094881548834488374883848845488464884948851488604886148865488704887348875488814889048894493024932549331

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering Ionia County

Ionia County shares a land border with 5 county equivalents. It has more land than 2 of them. The largest neighbor is Kent County (849.5 mi²) and the smallest is Barry County (553.1 mi²). Together with its neighbors, Ionia County forms a block of 3,821.9 mi² of land, of which it holds 14.9%.

How big is Ionia County compared with U.S. states?

Ionia County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.8 times as much. Michigan’s county land could hold about 99 areas the size of Ionia County.

Another way to picture it: the same land area would fill a square about 23.9 miles (38.5 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.

State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.

What stands out about Ionia County?

Ionia County has more land than 1,463 of the other 3,221 county equivalents in the dataset.

A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.

Does including water change its rank?

Using land plus water places Ionia County at #1,832 nationally by total area, 73 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.

Its water share is 1.5%, compared with a national county-equivalent median of 1.2% — 0.3 percentage points higher. This describes the statistical geography’s land/water mix, not flood exposure or developable land.

Closest positions in the national land ranking

These entries sit immediately beside Ionia County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.