| Name | Total | Name | Total |
|---|---|---|---|
| Oades | 1 | Orbin | 1 |
| Oakeley | 1 | Orchard | 2 |
| Oakes | 1 | Ord | 3 |
| Oakley | 1 | Orde | 3 |
| Oakman | 1 | Ordway | 1 |
| Oberpriller | 2 | Orkney, of | 2 |
| Ochitwa | 4 | Orleans, d' | 26 |
| ode Rumigny | 1 | Orléans-Longueville, d' | 3 |
| Odegard | 9 | Orr | 2 |
| Odingsells | 1 | Ortiz | 2 |
| Oelke | 1 | Orton | 1 |
| Oettingen-Spielberg | 1 | Osborn | 1 |
| Offen | 6 | Osborne | 6 |
| Ogden | 2 | Ost | 1 |
| Ogilvie-Grant | 1 | Osterhoudt | 1 |
| Ogle | 1 | Oswald | 1 |
| Ogley | 3 | Oswin | 1 |
| Oilly, de | 1 | Othick | 2 |
| Okeover | 1 | Otter | 9 |
| Old | 3 | Oudlap | 2 |
| Oldcorn | 2 | Oughton | 2 |
| Oldenburg | 2 | Outhwaite | 1 |
| Oldfield | 3 | Overfield | 1 |
| Oldham | 1 | Overton | 3 |
| Oldroyd | 1 | Overy | 1 |
| Oliphant | 1 | Owen | 6 |
| Oliver | 9 | Owens | 5 |
| Olson | 16 | Owston | 1 |
| Olsson | 1 | Oxburgh | 1 |
| Omer, St. | 3 | Oxby | 1 |
| ONeil | 2 | Oxenford | 6 |
| Onn | 1 | Oxford | 1 |
| OOSTENRIJK, van | 1 | Oxley | 3 |
| Oppenheimer | 1 | Oxtaby | 1 |
| Orange, of | 1 | Oxtoby | 7 |
| Oranje Nassau, van | 5 | Oyston | 1 |
| Orbais, d' | 1 | O’Neil | 2 |