| Name | What | Region | Country | Lat | Long | Elev Ft. | Pop Est |
|---|
| Okrivje | city | Primorsko-Goranska Zupanija | Croatia | 45.5661111 | 14.6677778 | 1732 | 5420 |
| Omar | city | Primorsko-Goranska Zupanija | Croatia | 45.1063889 | 14.9058333 | 3064 | 7266 |
| Omisalj | city | Primorsko-Goranska Zupanija | Croatia | 45.2088889 | 14.5563889 | 200 | 4734 |
| OmiĊĦalj | city | Primorsko-Goranska Zupanija | Croatia | 45.2088889 | 14.5563889 | 200 | 4734 |
| Opatija | city | Primorsko-Goranska Zupanija | Croatia | 45.3391667 | 14.3083333 | 0 | 6436 |
| Opatijo | city | Primorsko-Goranska Zupanija | Croatia | 45.3391667 | 14.3083333 | 0 | 6436 |
| Orehov Hrib | city | Primorsko-Goranska Zupanija | Croatia | 45.6416667 | 14.5886111 | 2837 | 4475 |
| Orehovica | city | Primorsko-Goranska Zupanija | Croatia | 45.3377778 | 14.4669444 | 734 | 7798 |
| Osilnica | city | Primorsko-Goranska Zupanija | Croatia | 45.5277778 | 14.6944444 | 1197 | 7519 |
| Oslinica | city | Primorsko-Goranska Zupanija | Croatia | 45.5277778 | 14.6944444 | 1197 | 7519 |
| Ostrovica | city | Primorsko-Goranska Zupanija | Croatia | 45.3330556 | 14.5933333 | 2017 | 8469 |
| Ostrovice | city | Primorsko-Goranska Zupanija | Croatia | 45.3330556 | 14.5933333 | 2017 | 8469 |