| Code | Name | Region |
|---|---|---|
| FR3IX | Ourville-en-caux | 76 |
| FRQST | Oust | 9 |
| FRO8M | Oust-marest | 80 |
| FROAE | Outarville | 45 |
| FROPC | Outreau | 62 |
| FROTZ | Outriaz | 1 |
| FROVL | Ouveillan | 11 |
| FROSJ | Osseja | 66 |
| FRQR3 | Osserain-rivareyte | 64 |
| FROES | Osses | 64 |
| FRWOH | Ostheim | 68 |
| FROHF | Osthoffen | 67 |
| FRO59 | Ostricourt | 59 |
| FROTW | Ostwald | 67 |
| FRPO4 | Ota | 2A |
| FRT8S | Othis | 77 |
| FROTG | Ottange | 57 |
| FROTE | Otterswiller | 67 |
| FROTM | Ottmarsheim | 68 |
| FRXOT | Ottrott | 67 |
| FROAV | Ouarville | 28 |
| FRD7D | Ouchamps | 41 |
| FROUC | Oucques | 41 |
| FROUD | Oudalle | 76 |
| FRXAL | Oudon | 44 |
| FROS2 | Ouessant | 29 |
| FROUG | Ouge | 70 |
| FROPN | Orphin | 78 |
| FRV8R | Orry-la-ville | 60 |
| FRQRO | Ors | 59 |
| FRPV9 | Orsan | 30 |
| FRS8N | Orsans | 11 |
| FRORS | Orsay | 91 |
| FRHRW | Orschwihr | 68 |
| FRWOR | Orschwiller | 67 |
| FRON9 | Orsennes | 36 |
| FRORT | Orthez | 64 |
| FRFXQ | Orthoux-serignac-quilhan | 30 |
| FRORV | Orval | 18 |
| FROVA | Orval | 50 |
| FRORU | Orvault | 44 |
| FRORI | Orville | 62 |
| FRWOB | Osenbach | 68 |
| FR8YU | Oslon | 71 |
| FR5IO | Os-marsillon | 64 |
| FROYM | Osmoy | 78 |
| FROSN | Osny | 95 |
| FRO6T | Oriolles | 16 |
| FRND5 | Orist | 40 |
| FRORR | Orleans | 45 |