| 5061 | Olympico d.o.o. | http://www.olympico.net |
| 5062 | Olymptours, agencija | http://www.olymp.hr |
| 5063 | Olympus d.o.o. | http://www.olympus.hr |
| 5064 | Omco d.d. | http://www.omco.hr |
| 5065 | Omega-Šped d.o.o. | http://www.omega-sped.hr |
| 5066 | Omgrad d.o.o. | http://www.omgrad.hr |
| 5067 | Omikron d.o.o. | http://www.omikron.hr |
| 5068 | Omiš - plivački maraton | http://www.omis-plmaraton.hr |
| 5069 | Omiš Wireless | http://www.omis-wireless.hr |
| 5070 | Omiš.info | http://www.omis.info |
| 5071 | Omni Modo d.o.o. | http://www.omnimodo.hr |
| 5072 | Omrčen promet d.o.o. | http://www.omrcen.hr |
| 5073 | OMV Istrabenz d.o.o. | http://www.omvistrabenz.hr |
| 5074 | OMV-Indoil d.o.o. | http://www.omv-indoil.hr |
| 5075 | Onix d.o.o. | http://www.onix-nekretnine.hr |
| 5076 | online turistička agencija - AdriaStar | http://www.adriastar.com |
| 5077 | Opatija - Apartman | http://opatija.way.to |
| 5078 | Opatija catering d.o.o. | http://www.opatijacatering.hr |
| 5079 | Opća bolnica Dr. J. Benčević | http://www.bolnicasb.hr |
| 5080 | Opća bolnica Koprivnica | http://www.obkoprivnica.hr |