Washington - Significance region: Local
| Mineau, Francis, House |
| Mineral Log Lodge |
| Minkler, Birdsey D., House |
| Mission Avenue Historic District |
| Moldenhauer, Dr. Hans & Rosaleen, House |
| Montague and McHugh Building |
| Monte Cristo Hotel |
| Montlake Historic District |
| Montvale Block |
| Moore, Edward B., House |
| Moore Theatre and Hotel |
| Moran State Park |
| Morgan, O. L. and Josephine, House |
| Morning Star Baptist Church |
| Morse Hardware Company Building |
| Morse House |
| Morse, Robert I., House |
| Mottman Building |
| Mount Baker Park and Boulevard |
| Mount Baker Park Historic District |
| Mount Baker Park Improvement Club Clubhouse |
| Mount Saint Michael |
| Mount Zion Baptist Church |
| Munson, Herbert and Barbara House |
| Murray, Frederick H., House |
| Muzzy-Shine House |
| MV WESTWARD (Wooden Motor Vessel) |
| National Bank of Tacoma |
| National Guard Armory - Olympia |
| Naval Lodge Elks Building |
| Naval Reserve Armory |
| Neely, Sr., Aaron and Sarah, Farm |
| Neighbor-Bennett House |
| Nelson, Albert, Farmstead |
| Nelson, Charles F., House |
| Nelson House |
| Nelson-Parker House |
| Nettleton's Addition Historic District |
| New Richmond Hotel |
| New Washington Hotel |
| Nifty Theatre |
| Nilsson, Andrew, House |
| Nine Mile Hydroelectric Power Plant Historic District |
| Ninth Avenue Historic District |
| Nisqually Power Substation |
| Nisqually School |
| Norman Bridge |
| North Bend Ranger Station |
| North Coast Casket Company Building |
| North Creek School |
| Northern Bank and Trust Building |
| Northern Pacific Railway Depot - Pullman |
| Northern Pacific Railway Passenger Depot |
| Northern Pacific Railway Passenger Depot |
| Northport School |
| Northrop Primary School |
| North Slope Historic District |
| Nuclear Reactor Building |
| Nutty Narrows Bridge |
| Oakesdale City Hall |
| Oakland Block |
| Oatman, Earl, House |
| Old City Hall |
| Old Georgetown City Hall |
| Old German Consulate |
| Old Main |
| Old North Yakima Historic District |
| Old Public Safety Building |
| Olsen, Ben, House |
| Olson, Louis and Ellen, House |
| Olson, Mary, Farm |
| Olympia Downtown Historic District |
| Olympia National Bank |
| Olympia Public Library |
| Olympic Club |
| Olympic Club Saloon |
| Opera House and I. O. O. F. Lodge |
| Opportunity Township Hall |
| Orcas Hotel |
| Orchard Terrace Apartments |
| Orr, Nathaniel, House and Orchard |
| Orton, Charles W., House |
| Osterman House |
| Otis Hotel |
| Pacific Brewing and Malting Company |
| Pacific National Bank Building |
| Pacific Telephone and Telegraph Building |
| Pagani, Luigi and Aurora, House |
| Palmer, A.L., Building |
| Palmer, Eben and Cynthia, Farmstead |
| Palmer, O. K., House |
| Palouse Main Street Historic District |
| Paramount Theatre |
| Paris, Joseph, House |
| Park Department, Division of Playgrounds |
| Parkland Lutheran Children's Home |
| Parson Smith Tree |
| Parsons, William, House |
| Pasco Carnegie Library |
| Patnude, Charles, House |
Data from United States Park Service and Wikidata
