| Name | Total | Name | Total |
|---|---|---|---|
| Orsama | 1 | Otollinen | 1 |
| Orsman | 1 | Otra-Aho | 2 |
| Ortala | 1 | Otranen | 4 |
| Ortela | 1 | Otronen | 1 |
| Ortju | 2 | Otsakari | 1 |
| Orvola | 1 | Otsamo | 2 |
| Orädd | 1 | Otsovaara | 1 |
| Osa | 2 | Otsovaara (Ent. Björn) | 1 |
| Osama | 1 | Ottela | 1 |
| Osanen | 1 | Ottelin | 3 |
| Osara | 5 | Ottman | 1 |
| Osenius | 3 | Ottoila | 1 |
| Oskanen | 1 | Ottonen | 4 |
| Oskura | 1 | Ottosson | 2 |
| Osma | 1 | Oukka | 1 |
| Osmala | 4 | Oukkonen | 1 |
| Osmalahti | 1 | Ouni | 1 |
| Osmio | 1 | Outavaara | 1 |
| Osmo | 1 | Outila | 1 |
| Osmonen | 1 | Outinen | 9 |
| Osola | 1 | Outonen | 1 |
| Osolaunus | 2 | Ouvinen | 1 |
| Ossi | 7 | Ovaska | 34 |
| Otalahti | 1 | Ovaskainen | 16 |