The following is a list of Michigan State Historic Sites in Ionia County, Michigan. Sites marked with a dagger (†) are also listed on the National Register of Historic Places in Ionia County, Michigan.__TOC__
| width="30%" | Name | width="100px" | Image | Location | width="125px" | City | width="125px" | Listing date | |
|---|---|---|---|---|---|---|---|---|---|
| Alvah N. Belding Memorial Library† | 302 East Main Street | Belding | |||||||
| Belding City Hall | 120 Pleasant Street | Belding | |||||||
| Belrockton Dormitory | 108 Hanover Street | Belding | |||||||
| John C. Blanchard House† | 253 East Main Street | Ionia | |||||||
| L. Phillip and Bertha Brock House | 409 Union Street | Ionia | |||||||
| Winslow P. Burhans House | 220 Rich Street | Ionia | |||||||
| Detroit, Lansing and Northern Railway Depot | Emerson Street | Lake Odessa | |||||||
| Louis P. Essick House | 644 East Main Street | Ionia | |||||||
| First Roadside Table Informational Site | Grand River Avenue, east of Morrison Lake Road, near Saranac | Saranac | |||||||
| Grand Trunk Western Saranac Depot | 138 S. Bridge St. | Saranac | |||||||
| Fred W. Green Informational Designation | 320 Union Street | Ionia | |||||||
| Frederick Hall House† | 126 East Main Street | Ionia | |||||||
| Homer-Holbrook Flour and Grist Mill (Burned/Demolished) | South Washington Street at Fish Creek | Hubbardston | |||||||
| Ionia Church of Christ | 130 East Washington Street | Ionia | |||||||
| Ionia County Courthouse† | 1000 East Main Street | Ionia | |||||||
| Oscar R. Long House | 144 East Main Street | Ionia | |||||||
| Lovell-Webber House† (demolished) | 111 East Main Street | Ionia | |||||||
| Lyons Prairie Site | SE 18, 07 N, 05 W, confluence of the Maple and Grand rivers | Lyons | |||||||
| Muir Church of Christ† | 138 Garden Street | Muir | |||||||
| John C. Olry Farmstead | 3226 East Musgrove Highway | Lake Odessa | |||||||
| Orleans Township District No. 10 School | 8013 N Decker Road | Orleans | |||||||
| Pere Marquette Railway Belding Depot† | 100 Depot Street | Belding | |||||||
| Portland First Congregational Church† | 421 East Bridge Street | Portland | |||||||
| Andrew B. Robinson House | 515 Ionia Street | Muir | |||||||
| St. John the Baptist Church / St. John the Baptist Cemetery† | 324 South Washington Street | Hubbardston | |||||||
| Saint John's Episcopal Church and Parish House | 107 West Washington Street, at Kidd Street | Ionia | |||||||
| Village of Saranac Informational Site | Entrance to Scheid Park, Main Street, between Fuller Street and Jackson Road | Saranac | |||||||
| Sessions Schoolhouse† | Riverside Drive at Jordan Lake Road | Ionia vicinity | |||||||
| Edward Stevenson General Store | 351 West Main Street | Ionia | |||||||
| Isaac H. Thayer House | 116 East High Street | Ionia | |||||||
| William H. VanderHeyden House† | 926 West Main Street | Ionia | |||||||
| Village of Smyrna Informational Site | 4972 Whites Bridge Road | Smyrna | |||||||
| Benjamin C. and Lucia Vosper House | 267 East Main Street | Ionia | |||||||
| Samuel Webber House | 644 East Bridge Street | Lyons | |||||||
| Weippert Mill | Northwest corner of Keefer Highway and Bippley Road | Sebewa | |||||||
| White's Covered Bridge (Destroyed by arson July 7, 2013) | Whitesbridge Road over the Flat River, south of 4 Mile Road | Keene Township | |||||||
| Women's Suffrage Amendment of 1918 Commemorative Designation | 252 Kent Street | Portland |