Michigan's 78th House of Representatives district (also referred to as Michigan's 78th House district) is a legislative district within the Michigan House of Representatives located in parts of Barry, Eaton, Ionia, and Kent counties.

[2] The district was created in 1965, when the Michigan House of Representatives district naming scheme changed from a county-based system to a numerical one.

[3] Lapeer County Tuscola County (part) Macomb County (part) St. Clair County (part) St. Clair County (part) Cass County Cass County