Maine - Role: Building
| Poland Railroad Station |
| Poland Spring Beach House, (Former) |
| Poland Spring Bottling Plant and Spring House |
| Pond Meeting House |
| Porteous, Mitchell and Braun Company Building |
| Porter-Bell-Brackley Estate |
| Porter Memorial Library |
| Porter Old Meetinghouse |
| Portland Breakwater Light |
| Portland City Hall |
| Portland City Hospital |
| Portland Club |
| Portland Headlight |
| Portland High School |
| Portland Observatory |
| Portland Packing Company Factory |
| Portland Railroad Company Substation |
| Portsmouth Company Cotton Mills: Counting House |
| Pote, Capt. Greenfield, House |
| Powder House Lot |
| Powers House |
| Powers, Peter, House |
| Pownalborough Courthouse |
| Prescott, J. L., House |
| Presque Isle National Bank |
| Pressey House |
| 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 |
| Quimby, Dr. Samuel, House |
| Quincy Building |
| Rackleff Building |
| Ramsdell, Hiram, House |
| Randall-Hildreth House |
| Randall, Jacob, House |
| Rangeley Tavern |
| Rangeley Trust Company Building |
| Rangley Public Library |
| Rankin Block |
| Raventhorp |
| Readfield Union Meeting House |
| Record, E.C. and M.I., Homestead |
| Record, Judson, House |
| Red Brick School |
| Redington House |
| Redwood |
| Reed, G. W., Travellers Home |
| Reed, Philo, House |
| Reed, Robert, House |
| Reed School |
| Reed, Thomas Brackett, House |
| Reverie Cove |
| Rice Public Library |
| Richardson House |
| Riggs, Benjamin, House |
| Riggs-Zorach House |
| River Meetinghouse |
| Riverview House |
| Roak Block |
| Robinhood Free Meetinghouse |
| Robinson, Edward Arlington, House |
| Robinson-Parsons Farm |
| Robinson, William A., House |
| Rockland Breakwater Lighthouse |
| Rockland Public Library |
| Rockland Railroad Station |
| Rock Rest |
| Roosevelt School |
| Roosevelt School |
| Ropes End |
| Rose, Robert, Tavern |
| Row House |
| Ruggles House |
| Rumford Center Meeting House |
| Rumford Falls Power Company Building |
| Rumford Point Congregational Church |
| Rumford Public Library |
| Rural Hall |
| Russwurm, John B., House |
| Saco Central Fire Station |
| Saco City Hall |
| Saco High School (old) |
| Sail Loft |
| Saint Jude's Episcopal Church |
| Saint Mary's General Hospital |
| Saint Saviour's Episcopal Church and Rectory |
| Salem Town House (Former) |
| Sanford Town Hall (Former) |
| Sangerville Town Hall |
| Sargent, Levi, House |
| Sargent-Roberts House |
| Savings Bank Block |
| Scarborough High School |
| Schlotterbeck and Foss Building |
| Scott, Capt. George, House |
Data from United States Park Service and Wikidata
