Ohio - Significance region: Local
| Pleasant Ridge United Methodist Church and Cemetery |
| Plymouth Greenlawn Cemetery Chapel |
| Plymouth Historic District |
| Poinciana Flats |
| Point, Nathaniel, Farm |
| Poland Center School |
| Police Station No. 2 |
| Police Station No. 3 |
| Police Station No. 5 |
| Police Station No. 6 |
| Police Station No. 7 |
| Pollack, Isaac, House |
| Pollock, John C., House |
| Pollock Works |
| Pomeroy, Alanson, House |
| Portage Hotel |
| Portage Street Elementary School |
| Port Clinton City Hall |
| Porter-Aue House |
| Porter, Orin, House |
| Port Jefferson School |
| Portsmouth Fire Department No. 1 |
| Portsmouth Foundry and Machine Works |
| Port Washington Town Hall |
| Potter, Carl, Mound |
| Potter’s Field - West Price Hill |
| Potters National Bank |
| Potters Savings and Loan |
| Pottorf, Henry and Mary, House and Farmstead |
| Powell, Andrew, Homestead |
| Power Building |
| Pray-Starkweather House |
| Presbyterian Parsonage |
| Pretzinger, Rudolph, House |
| Price Corners |
| Price, Jonathan, House |
| Principal's Cottage |
| Pringle-Patric House |
| Probasco, Henry, House |
| Procter and Collier-Beau Brummell Building |
| Prospect Avenue Row House Group |
| Prospect Hill Historic District |
| Providence Historic District |
| Provident Savings Bank and Trust Co. |
| Pugh-Kittle House |
| Purcell, Robert A. and Elizabeth H., House |
| Purdum-Tracy House |
| Putman, Walter S., House |
| Pythian Castle |
| Pythian Temple and James Pythian Theater |
| Quad Hall |
| Race Street Historic District |
| Radnor Township Hall |
| Rae, Capt., House |
| Raemelton Farm Historic District |
| Rager, John, Farmhouse |
| Ragersville School |
| Railway Chapel, The |
| Raleigh Mound |
| Randall, Dr. Rufus, Residence |
| Ranger Station Mound |
| Rankin Building |
| Ranney, Luther B., Farm |
| Ransbottom, C. W., House |
| Ransbottom, Edward, House |
| Ransbottom, Frank M., House |
| Ransbottom, Mort, House |
| Ratcliffe Mound |
| Ratterman, Bernard, House |
| Rattermann, Heinrich A., House |
| Rauch & Lang Carriage Company Building |
| Rauh, Frederick and Harriet, House |
| Rawlings-Brownell House |
| Rawson House |
| Rayen School |
| Raymond, Frank Mason, House |
| Raymond, Liberty G., Tavern and Barn |
| Reakirt Building |
| Realty Building |
| Reamer Barn |
| Reaves, John, House |
| Reber, Valentine, House |
| Record Rendezvous |
| Redington Block |
| Redlands |
| Red Oak-Sherman, William C., House |
| Red Popcorn Wagon |
| Reed, C. A., House |
| Reed Covered Bridge |
| Reed, Henry, Jr., House |
| Reed, James, House |
| Reed, Joseph G., Company |
| Reefy, Frederick, House |
| Reeser, C. A., House |
| Reeves, Jeremiah, House and Carriage House |
| Reeves Mound |
| Regal Theater |
| Reidy Bros. & Flanigan Building |
| Reily, Robert, House |
| Renick Farm |
Data from United States Park Service and Wikidata
