Iowa - Significance region: Local
| Petersen's, J. H. C., Sons Store |
| Petersen, W. D., Memorial Music Pavillion |
| Peters, J. C., House |
| Peterson Manufacturing Building |
| Picklum, Frank, House |
| Pierce School No. 13 |
| Pierson-Betts House |
| Pilotburg Church |
| Pilot Grove |
| Pine Mills German Methodist Episcopal Church |
| Pioneer Implement Company |
| Pioneer Oil Company Filling Station |
| Plambeck, Joachim, House |
| Plane, Robert R., and Julia L., House |
| Pleasant Grove Community Church and Cemetery |
| Pleasant Grove Presbyterian Church |
| Pleasant Hill School |
| Pleasant View Stock Farm Historic District |
| Plymouth County Courthouse |
| Plymouth Place |
| Pocahontas County Courthouse |
| Podhajsky-Jansa Farmstead District |
| Pohlmann, Elizabeth, House |
| Pohlmann, Henry, House |
| Poldberg, Chris, Farmstead |
| Polk County Homestead and Trust Company Addition Historic District |
| Pony Creek Park |
| Porter Hall |
| Porter-Rhynsburger House |
| Pottawattamie County Sub Courthouse |
| Potter's, E. G., Jasper Flour Mill |
| Potter-Williams House |
| Poweshiek County Courthouse |
| Prairie Center Methodist Episcopal Church and Pleasand Hill Cemetery |
| Prairie Grove School |
| Pratt, A. W., House |
| Presbyterian Church |
| President's Cottage |
| Preston’s Station Historic District |
| Price, Hiram/Henry Vollmer House |
| Price, Rialto, House |
| Prien Building |
| Priester Building, The |
| Primrose Mill |
| Princess-Sweet Shop |
| Prospect Park Historic District |
| Prospect Park Second Plat Historic District |
| Public Library of Des Moines |
| Public Square Historic District |
| Pucker Street Historic District |
| Purdy, Eliphalet W. and Catherine E. Jaquish, House |
| Putnam-Parker Block |
| Pyle, Glenn O. and Lucy O., House |
| Quasdorf Blacksmith and Wagon Shop |
| Queen, Hogan and Martha A. Runkle, House |
| Quickel, Jacob, House |
| Radcliff, Willam, House |
| Raible, F. J., House |
| Rambo House |
| Ramsey Building |
| Ranshaw, Samuel and Emma A., House |
| Ranzow-Sander House |
| Raphael, Jacob, Building |
| Rath, Johann Christian Frederick, House |
| Rath Packing Company Administration Building |
| Ray, Frank G., House & Carriage House |
| Raymond, P. P., House |
| Rector, Jason and Elizabeth Baylor, House |
| Red Ball Garage |
| Redfield GAR Hall |
| Redmond Park-Grande Avenue Historic District |
| Red Oak Downtown Historic District |
| Red Oak Firehouse and City Jail |
| Red Oak Grove Presbyterian Church and Cemetery |
| Red Oak High School |
| Reeve, Leander, House |
| Reeves, Isaac and Agnes (Bells), House |
| Regina Coeli Monastery |
| Register and Tribune Building |
| Reichert, John Christian and Bertha Landrock, House |
| Renken, Renke and Wubke, House |
| Renwick Building |
| Renwick Generating Plant |
| Renwick House |
| Reverend Little's Young Ladies Seminary |
| Rewerts, George, House |
| Reynolds, Anson O., House |
| Reynolds, Charles B., Round Barn |
| Rhodes Mill |
| Richardson-Jakway House |
| Rick's Brewery |
| Riekenberg, J. H., House |
| Riemenschneider, August and Josephine, Farmstead |
| Ringgold County Courthouse |
| Ringgold County Jail |
| Rittenmeyer, F. X., House |
| Riverview Park Plat Historic District |
| Riverview Terrace Historic District |
| Robb House and Spring House |
| Roberts, Edward C., House |
Data from United States Park Service and Wikidata
