Indiana - Significance region: Local
| Normain Heights Historic District |
| Normal Hall |
| Norris Farm-Maxinkuckee Orchard |
| North Anthony Boulevard Historic District |
| Northern States Life Insurance Company |
| North Irvington Gardens Historic District |
| North Jefferson Street Historic District |
| North Liberty Commercial Historic District |
| North Liberty Park |
| North Manchester Covered Bridge |
| North Manchester Historic District |
| North Manchester Public Library |
| North Meridian Street Historic District |
| North Pennsylvania Street Historic District |
| North Pumping Station |
| Northside Boulevard Riverwall |
| North Street Viaduct |
| North Vernon Downtown Historic District |
| North Wabash Historic District |
| North Washington Street Historic District |
| Northwood Historic District |
| Norton, C. S., Mansion |
| Nowels, David & Sarah, House |
| Nurses' Sunken Garden and Convalescent Park |
| Oakalla Covered Bridge |
| Oakdale Historic District |
| Oakdale School |
| Oak Hill Cemetery |
| Oaklandon Historic District |
| O'Brien Electric Priming Company |
| O'Donnell Building |
| O'Hair, James Edington Montgomery, House |
| Ohio Boulevard-Demming Park Historic District |
| Ohio Street Bridge |
| Old Bittermann Building |
| Old Clifty Church |
| Old Courthouse (Second St. Joseph County Courthouse) |
| Old East Historic District |
| Olde Store (John O'Ferrell Store) |
| Old Fellwock Auto Company |
| Old Frankfort Stone High School |
| Old Greencastle Historic District |
| Old Hoosier Theatre |
| Old Newburgh Presbyterian Church |
| Old Perry County Courthouse |
| Old Plat Historic District |
| Old Silk Stocking Historic District |
| Old Timbers |
| Old Vanderburgh County Courthouse |
| Old Warrick County Jail |
| Old West End Historic District |
| O'Neall, Abijah II, House |
| Oriental Lodge No. 500 |
| Original Newburgh Historic District |
| Orleans Historic District |
| Orr Iron Company |
| Osgood, Dr. H. G., House |
| Otis Park and Golf Course |
| Otter Creek Covered Bridge |
| Our Savior Lutheran Church |
| Owen County Courthouse |
| Oxford |
| Oxford Hotel |
| Palace Lodge |
| Palace Theater |
| Paoli Historic District |
| Paramount Theater Building |
| Parker, Oren F. and Adelia, House |
| Park Mary Historic District |
| Parkview Home of Clinton County |
| Parson and Scoville Building |
| Parsons, A.A., Farmstead |
| Patoka Bridges Historic District |
| Patoka Church of God in Christ-Patoka Colored School |
| Patterson, J.W., House |
| Patterson Place Historic District |
| Peabody Memorial Tower |
| Peacock Apartments |
| Pearl Steam Laundry |
| Pearson, Lora B., School |
| Pearson Terrace |
| Peirce, Oliver Webster Jr., and Catherine House |
| Pendleton Historic District |
| Pennslyvania Railroad Station |
| Pennsylvania |
| Pennsylvania Railroad Station |
| Perrin Historic District |
| Peru Courthouse Square Historic District |
| Peru High School Historic District |
| Peru Westside Historic District |
| Peters, Henry, House |
| Peters, John Claus, House |
| Picnic Area-Jackson State Forest |
| Pierce, James, Jr., House |
| Pierceton Historic District |
| Pike County Courthouse |
| Pike Inn, Old |
| Pine Bluff Covered Bridge |
| Pinehurst Hall |
| Pipe Creek Falls Resort |
Data from United States Park Service and Wikidata
