| O'Bannon | 5 |
| O'Brien | 1 |
| O'Bryant | 1 |
| O'Bryon | 1 |
| O'Connell | 1 |
| O'dair | 1 |
| O'dear | 1 |
| O'Dell | 2 |
| O'Grady | 1 |
| O'Hare | 1 |
| O'Leary | 10 |
| O'Neal | 1 |
| O'Neill | 1 |
| O'Steen | 1 |
| O'Sullivan | 1 |
| Oak | 1 |
| Oakes | 1 |
| Oberdeck | 1 |
| Obernier | 1 |
| OConner | 1 |
| Odell | 1 |
| Oden | 1 |
| Odom | 1 |
| Odum | 2 |
| Oelke | 2 |
| Offutt | 1 |
| Ogden | 4 |
| Oldham | 2 |
| Olinger | 1 |
| Oliphant | 1 |
| Oliver | 7 |
| Olson | 2 |
| Oney | 1 |
| Oren | 1 |
| Oriard | 10 |
| Orr | 6 |
| Osborne | 33 |
| Osenbaugh | 2 |
| Osterude | 4 |
| Ottwell | 1 |
| Overbaker | 1 |
| Overdeck | 3 |
| Overstreet | 1 |
| Overton | 5 |
| Owen | 6 |
| Owens | 17 |
| Owsley | 4 |
| Oxnard | 2 |
| Oyler | 1 |
updated - GMB 06/16/07