Ohio - Significance region: Local
| Marlow Theatre |
| Marmon, Martin, House |
| Marquart-Mercer Farm |
| Marshall, David, House |
| Marshall, James E., House |
| Marsh, George H., Homestead and the Marsh Foundation School |
| Marsh, Joseph, House |
| Martin Block and Kibby Block |
| Martin, Brooke and Anna E. House |
| Martindale, Samuel, House |
| Marting Hotel |
| Martin, Henry, Farm |
| Martin House |
| Martin, Joseph, House |
| Marvin Memorial Library |
| Marysville Light and Water Company Plant |
| Mason, Frank H., House |
| Mason House |
| Masonic Lodge #472 |
| Masonic Temple |
| Masonic Temple |
| Masonic Temple |
| Masonic Temple Building |
| Masonic Temple Building |
| Masonic Temple Price Hill Lodge, No. 524 |
| Mason, James, House |
| Massillon Cemetery Building |
| Massillon Downtown Historic District |
| Mater Dei Chapel |
| Mather, Flora Stone, College District |
| Mathew Mound |
| Mattoon-Woodrow House |
| Maudru House |
| Maumee Historic District |
| Maumee Theater |
| Maumee Uptown Historic District |
| May Company |
| May, David and Mary, House |
| Mayfield Heights Historic District |
| Mayfield Theatre Building, The |
| May Realty Building |
| McBean, Daniel, Farmstead |
| McCafferty Run Farmstead |
| McCafferty, William, Farmhouse |
| McCarthy-Blosser-Dillon Building |
| McClelland, Harry S., House |
| McClure-Nesbitt Motor Company |
| McConnelsville Historic District |
| McCorkle, Almon G., House |
| McCormick Manufacturing Company Building |
| McCracken-McFarland House |
| McCracken-Scott House |
| McCracken-Sells House |
| McCrea, Matthew, House |
| McCreary-Burnworth House |
| McCully Log House |
| McCune's Villa |
| McDaniel Mound |
| McDannald Homestead |
| McDonald Farm |
| McDowell, Austin, House |
| McDowell, R.M. and Elizabeth, House |
| McFarland, Duncan, House |
| McFarland, James, House |
| McGraw House |
| McIntire Terrace Historic District |
| McKee-Pumphrey House |
| McKenster-Groff House |
| McKever, Lewis, Farmhouse |
| McKinley Memorial |
| McKinley Park Apartments |
| McKinley School |
| McKinley School |
| McKinley School |
| McKinley Terrace |
| McKisson, Robert, House |
| McKitrick, Dr., House |
| McKitrick, Dr., Office |
| McLain-Gillmer House |
| McLaughlin Mound |
| McMillan, Reuben, Free Library |
| McNamar-McLure-Miller Residence |
| McPherson Town Historic District |
| McSweeney, John, House |
| McWilliams, Matthew, House |
| Mead House |
| Mead-Zimmerman House |
| Mechanics Building and Loan Company |
| Mecklenburg's Garden |
| Medfair Heights Apartment Historic District |
| Medical Centre Building |
| Medina County Courthouse |
| Medina Farmers Exchange Co. |
| Medina Masonic Temple and Medina Theater |
| Meeker, Forrest, House and Farm |
| Meek, J.F., Buildings |
| Meigs County Fairgrounds, Grandstand and Racetrack |
| Meister Apartments, The |
| Melbourne Flats |
| Melick Mound |
Data from United States Park Service and Wikidata
