| Name | What | Region | Country | Lat | Long | Elev Ft. | Pop Est |
| Opacica Dolina | city | | Croatia | 44.5694444 | 15.96 | 2339 | 3597 |
| Opacici | city | | Croatia | 44.1416667 | 15.3236111 | 226 | 3398 |
| Opacici | city | | Croatia | 44.12 | 15.5211111 | 800 | 3431 |
| Opacki | city | | Croatia | 43.2897222 | 17.2861111 | 2460 | 10525 |
| Opalic | city | | Croatia | 44.4688889 | 15.7352778 | 2201 | 3410 |
| Opalić | city | | Croatia | 44.4688889 | 15.7352778 | 2201 | 3410 |
| Opaljene Klade | city | | Croatia | 44.6433333 | 15.9611111 | 2227 | 4311 |
| Opanci | city | | Croatia | 43.4833333 | 16.9833333 | 1660 | 10714 |
| Opatija | city | | Croatia | 45.5666667 | 16 | 557 | 9883 |
| Opatijski Torovi | city | | Croatia | 43.9511111 | 15.4652778 | 49 | 2307 |
| Opatinec | city | | Croatia | 45.7166667 | 16.3833333 | 331 | 5471 |
| Opatinski | city | | Croatia | 43.9511111 | 15.4652778 | 49 | 2307 |
| Opatovac | city | | Croatia | 45.2605556 | 19.1708333 | 406 | 9712 |
| Opačića Dolina | city | | Croatia | 44.5694444 | 15.96 | 2339 | 3597 |
| Opačići | city | | Croatia | 44.1416667 | 15.3236111 | 226 | 3398 |
| Opačići | city | | Croatia | 44.12 | 15.5211111 | 800 | 3431 |
| Opački | city | | Croatia | 43.2897222 | 17.2861111 | 2460 | 10525 |
| Oporovec | city | | Croatia | 46.3319444 | 16.6752778 | 472 | 15399 |
| Oprisavci | city | | Croatia | 45.1511111 | 18.2297222 | 265 | 8223 |
| Oprisovci | city | | Croatia | 45.1511111 | 18.2297222 | 265 | 8223 |
| Opsenjak | city | | Croatia | 43.8594444 | 16.5641667 | 3156 | 10613 |
| Opus | city | | Croatia | 43.0152778 | 17.5655556 | 22 | 7320 |
| Opuzen | city | | Croatia | 43.0152778 | 17.5655556 | 22 | 7320 |
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