| 5221 | OŠ T. Ujević | http://www.os-tin-ujevic.hr |
| 5222 | Otis Hrvatska | http://www.otis.com |
| 5223 | Otisak d.o.o. | http://www.otisak.hr |
| 5224 | Otočki vjesnik | http://www.otocki.hr |
| 5225 | Otok mladosti d.o.o. | http://www.otok-mladosti.hr |
| 5226 | Otok Molat | http://www.molat.net |
| 5227 | Otok Pašman | http://www.islandpasman.com |
| 5228 | Otok Silba | http://www.silba-island.com |
| 5229 | Otok Solta - Villa Ruic | http://www.villaruic.com |
| 5230 | Otok znanja | http://www.otok-znanja.hr |
| 5231 | Otos Ortopedska tehnika d.o.o. | http://www.otos.hr |
| 5232 | OTŠ Ogulin | http://www.otsog.hr |
| 5233 | OTTO - Kataloška prodaja d.o.o. | http://www.otto.hr |
| 5234 | Otvorena vrata | http://www.otvorena-vrata.hr |
| 5235 | Ouroboros IT (Ouroboros d.o.o.) | http://it.ouroboros.hr |
| 5236 | Outfit d.o.o. | http://www.outfit.hr |
| 5237 | Ovčiji sir Lušić | http://www.lusic.com |
| 5238 | Overseas Express | http://www.overseas.hr |
| 5239 | OXY d.o.o. | http://www.oxy.hr |
| 5240 | Ozana d.o.o. | http://www.ozana.hr |