| Zip Code | City | Population ↓ |
|---|---|---|
| 48846 | Ionia | 22,038 |
| 48809 | Belding | 11,112 |
| 48875 | Portland | 10,899 |
| 48849 | Lake Odessa | 5,789 |
| 48881 | Saranac | 5,521 |
| 48851 | Lyons | 2,307 |
| 48815 | Clarksville | 2,254 |
| 48865 | Orleans | 1,918 |
| 48860 | Muir | 1,601 |
| 48873 | Pewamo | 1,402 |
| 48845 | Hubbardston | 981 |
| 48870 | Palo | 214 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 12 ZCTAs in Ionia County, Michigan (US Census).