The Diocese of Lansing (Latin: Diœcesis Lansingensis) is a Latin Church ecclesiastical territory or diocese of the Catholic Church located in the south-central portion of Michigan around Lansing. It encompasses an area of 6,218 square miles (16,100 km2) including the counties of Clinton, Eaton, Genesee, Hillsdale, Ingham, Jackson, Lenawee, Livingston, Shiawassee and Washtenaw. The Diocese of Lansing is a suffragan diocese in the ecclesiastical province of metropolitan Archdiocese of Detroit.