| OAKES | Olive Christian |
| OAKLEY | Mooresville, Greenlawn |
| OBENSHAIN | Old Baptist |
| O' BRIEN | Mooresville |
| O' CAIN | Friendship Park |
| O' CONNER | Mannan |
| O' DELL | Mount Tabor |
| O' DENNELL | Mooresville |
| ODOM | Mooresville |
| O' DONNELL | Mount Nebo |
| OGLE | Walters, Mooresville |
| OGLES | Walters, Mannan, New Salem Baptist |
| O' HARROW | Centennial, Williams, Greenlawn |
| O' HORROW | Greer, Odd Fellows |
| O' HULLANE | Mannan |
| OLDS | North Branch, Williams (Washington Twp) |
| OLIVER | Lingle, Olive Christian, Mooresville, Easthill, Mount Nebo, Bethlehem, Mount Gilead, Hilldale, Williams (Washington Twp) |
| OLLEMAN | Mooresville |
| OLSEN | Liberty |
| OMER | Mount Pleasant |
| OMRI | Mooresville |
| O' NEAL | Olive Christian, Bethlehem, Mount Olive (Jefferson Twp), Shultz, Greenlawn |
| O' NEILL | Mooresville, Mount Gilead |
| OOLEY | Friendship Park |
| OPPLE | Mooresville |
| ORNER | Hilldale |
| ORPHA | Friendship Park |
| ORR | Centerton, Union Chapel |
| ORRELL | Samaria |
| OSA | Mooresville |
| OSBORN | Mooresville, Hynds |
| OSBORNE | Shumaker, Mooresville, West Union |
| OTEY | Friendship Park |
| OVERMAN | Mooresville, West Union, Samaria |
| OVERSTREET | Cunningham Hill |
| OVERTON | Mooresville, Brooklyn, West Union, Greenlawn |
| OWEN | Mooresville, Pearce Family, Poplar Grove, Bethesda, Hilldale |
| OWENS | Olive Christian, Union Christian, Brooklyn, Friendship Park, Gose Creek, Greenlawn, South Park |
| OZMENT | Mooresville |
