Ionia, Michigan

Ionia, Michigan
Aerial view of Ionia, Michigan in 2025
Interactive map of Ionia, Michigan
Ionia
Ionia
Coordinates: 42°58′37″N 85°04′29″W / 42.976821°N 85.074633°W / 42.976821; -85.074633
CountryUnited States
StateMichigan
CountyIonia
SettledMay 1833
Platted1841
Incorporated as a village1865
Organized into a city1873
Government
 • MayorJohn R. Milewski, II
Area
 • Total
5.542 sq mi (14.354 km2)
 • Land5.412 sq mi (14.016 km2)
 • Water0.131 sq mi (0.340 km2)  2.36%
Elevation
633 ft (193 m)
Population
 (2020)
 • Total
13,378
 • Estimate 
(2024)
12,265
 • Density2,472.1/sq mi (954.48/km2)
Time zoneUTC−5 (Eastern (EST))
 • Summer (DST)UTC−4 (EDT)
ZIP Code
48846
Area code616
FIPS code26-40860
GNIS feature ID1626521
Websitecityofionia.org

Ionia (/ˈnjə/ eye-OH-nyə) is the largest city in and the county seat of Ionia County, Michigan, United States. The population was 13,378 at the 2020 census, and was estimated at 12,265 in 2024. Every July it hosts what is said to be the world's largest free-admission fair, the Ionia Free Fair. The city is mostly within Ionia Township, with small portion extending into Easton Township and Berlin Township, but is politically autonomous of the townships. The city is named after Ionia, a historic region in Greece.