Maine - Significance region: Local
| Philler Cottage |
| Phillips High School |
| Pike, LeRoy F., Memorial Building |
| Pike's Mile Markers |
| Pilley House |
| Pilsbury Block |
| Pittsfield Public Library |
| Pittsfield Railroad Station |
| Pittston Congregational Church |
| Pittston Farm |
| Pleasant River Grange No. 492 |
| Plummer, Capt. John, House |
| Poland Railroad Station |
| Poland Spring Beach House, (Former) |
| Porteous, Mitchell and Braun Company Building |
| Porter-Bell-Brackley Estate |
| Porter Memorial Library |
| Porter-Parsonfield Bridge |
| Portland Breakwater Light |
| Portland City Hall |
| Portland City Hospital |
| Portland Club |
| Portland Headlight |
| Portland High School |
| Portland Packing Company Factory |
| Portland Railroad Company Substation |
| Portland Soldiers and Sailors Monument |
| Portland Waterfront |
| Portsmouth Company Cotton Mills: Counting House |
| Pote, Capt. Greenfield, House |
| Powder House Lot |
| Powers House |
| Powers, Peter, House |
| Pownal Cattle Pound |
| Prescott, J. L., House |
| Presque Isle National Bank |
| Primrose Hill Historic District |
| Prince, Cushing and Hannah, House |
| Professional Building |
| Proprietors Meeting House and Parish House |
| Prouty, Jed, Tavern and Inn |
| Purington, Elisha, House |
| Purinton Family Farm |
| Putnam, Blackhawk, Tavern |
| Pythian Opera House |
| Quartz Scraper Site |
| Quimby, Dr. Samuel, House |
| Quincy Building |
| Rackleff Building |
| Ramsdell, Hiram, House |
| Randall-Hildreth House |
| Randall, Jacob, House |
| Rangeley Lakes Country Club Historic District |
| Rangeley Tavern |
| Rangeley Trust Company Building |
| Rangley Public Library |
| Rankin Block |
| Raventhorp |
| Record, E.C. and M.I., Homestead |
| Record, Judson, House |
| Red Brick School |
| Redington House |
| Reed, G. W., Travellers Home |
| Reed, Philo, House |
| Reed, Robert, House |
| Reed School |
| Rendezvous Point Burying Ground |
| Reverie Cove |
| Reversing Falls Site |
| Rice Public Library |
| Richardson House |
| Richmond Historic District |
| Riggs, Benjamin, House |
| Rivercroft Farm |
| Riverview House |
| Robertson Quarry Galamander |
| Robinhood Free Meetinghouse |
| Robinson-Parsons Farm |
| Robinson, William A., House |
| Robyville Bridge |
| Rockland Breakwater |
| Rockland Breakwater Lighthouse |
| Rockland Public Library |
| Rockland Railroad Station |
| Rockland Residential Historic District |
| Rockland Turntable and Engine House |
| Roosevelt School |
| Roosevelt School |
| Ropes End |
| Rose, Robert, Tavern |
| Row House |
| Rumford Center Meeting House |
| Rumford Commercial Historic District |
| Rumford Falls I-IV Site |
| Rumford Falls Paper Company Historic District |
| Rumford Falls Power Company Building |
| Rumford Falls V Site |
| Rumford Public Library |
| Rural Hall |
| Saco Central Fire Station |
Data from United States Park Service and Wikidata
