| Marquisate | Province | Department | Time of Creation | Type | Receiving family | Current status | Comments |
|---|---|---|---|---|---|---|---|
| O | Normandie | 61 | late 15__ | LP | d'O | Extinct 1827 | |
| O | Normandie | 61 | 1616 | C LP | de la Guesle | Extinct 1827 | |
| OILLIAMSON | Normandie | 14 | 1739 | LP | d'Oilliamson | Extant | based on previous marquisate de SAINT-GERMAIN |
| OLHONCE | Navarre | 64 | 1758 | LP | Carbajales d'Olhonce | Extinct 1911 | |
| OLLIÈRES | Provence | 83 | 1689 | LP | d'Agoult d'Ollières | Extinct 1820 | |
| OLLONE | Comtat-Venaissin | 84 | 1754 | LP | de Tillia | Extinct 1856 | papal title |
| OLONDE(-HARCOURT) | Normandie | 50 | early 17__ | BR | d'Harcourt d'Olonde | Extant | |
| OMS | Roussillon | 66 | 1767 | LP | d'Oms de Tord | Extinct 1809 | |
| OPPÈDE | Provence | 84 | early 16__ | LP | de Forbin-Maynier | Extinct 1900 | |
| ORIVAL | Picardie | 80 | late 16__ | LP | de Riencourt d'Orival | Extinct 1858 | |
| ORMESSON | Île-de-France | 94 | 1758 | LP | le Fèvre d'Ormesson | Extant | |
| ORNACIEUX | Dauphiné | 38 | 1645 | LP | de la Croix-Chevrières de Sayve | Extant | |
| OUËSSANT | Bretagne | 29 | 1595 | LP | de Rieux de Sourdéac | Extinxt 1793 | Royal domain since 1764 (purchase) |
| OYSONVILLE | Chartrain | 28 | 1664 | LP | le Prévost | Extant | title transferable by marriage; belongs to Odart de Rilly since 1851 |
| OZILLAC | Saintonge | 17 | 1623 | LP | de Sainte-Maure-Jonzac | Extinct 1791 |
Read more about this topic: List Of French Marquisates