O
| Title | Date of creation | Surname | Current status | Notes |
|---|---|---|---|---|
| Oglander of Nunwell | 1665 | Oglander | extinct 1874 | |
| Oldfield of Spalding | 1660 | Oldfield | extinct 1705 | |
| Onslow of West Clandon | 1674 | Onslow | extant | created Baron Onslow (1716) in the Peerage of Great Britain; Earl Onslow (1801) in the Peerage of the United Kingdom. |
| Orby of Croyland | 1658 | Orby | extinct 1725 | |
| Osbaldeston of Chadlington | 1664 | Osbaldeston | extinct 1749 | |
| Osborn of Chicksands | 1662 | Osborn | extant | |
| Osborne of Kiveton | 1620 | Osborne | extinct 1964 | created Duke of Leeds (1694) in the Peerage of England. |
| Owen of Orielton | 1641 | Owen, Owen-Barlow | extinct 1851 | |
| Oxenden of Dene | 1678 | Oxenden, Dixwell-Oxenden | extinct 1924 |
Read more about this topic: List Of Baronetcies In The Baronetage Of England