| Os Elektro Eiendom AS | Real estate | 2022 |
| Os Fargehandel AS | Wholesale & retail | 1986 |
| Os Filmsenter AS | Administrative & support | 2009 |
| Os Gravferdsbyrå AS | Other services | 2002 |
| Os Hageservice AS | Administrative & support | 2008 |
| Os Hud Og Hår AS | Other services | 1994 |
| Os Hus AS | Real estate | 2011 |
| Os Håndverk AS | Construction | 2016 |
| Os Industrirens AS | Administrative & support | 2025 |
| Os Kafé Og Restaurant AS | Hospitality | 2025 |
| Os Lavpris AS | Wholesale & retail | 1998 |
| Os Live AS | Administrative & support | 2016 |
| Os Manuellterapi & Fysioterapi AS | Health & social care | 2009 |
| Os Maritim Consult AS | Professional & scientific | 2025 |
| Os Næringspark AS | Real estate | 2022 |
| Os Og Fusaposten AS | Information & communication | 1987 |
| Os Parkering AS | Transport & logistics | 2010 |
| Os Reisebyrå AS | Administrative & support | 1980 |
| Os Revisjon Ans | Professional & scientific | 1996 |
| Os Røde Kors Eiendom AS | Real estate | 2006 |
| Os Servicebakeri AS | Hospitality | 2019 |
| Os Tannteknikk AS | Manufacturing | 2013 |
| Os Taxi AS | Transport & logistics | 2004 |
| Os Tipp Og Jordsortering AS | Mining & quarrying | 2013 |
| Os Utleie AS | Administrative & support | 2022 |
| Osbygg AS | Construction | 2012 |
| Oselvo AS | Construction | 2020 |
| Oshaugen 14 AS | Real estate | 2012 |
| Osroso AS | Hospitality | 2020 |
| Osøyro Bakeri AS | Manufacturing | 2024 |
| Osøyro Invest AS | Real estate | 2020 |
| Osøyro Kolonial AS | Manufacturing | 2016 |
| Ouro AS | Information & communication | 2012 |
| Ovc AS | Information & communication | 2013 |
| Overflatesenteret AS | Real estate | 1986 |
| Ovm AS | Financial services | 2016 |
| Os Maskinering Haugland og Mo ANS | Manufacturing | 1981 |
| Paal Sine Høner AS | Real estate | 2016 |
| Panora AS | Wholesale & retail | 2024 |
| Partner Hus & Service Bygg AS | Construction | 2025 |
| Partner Vegabra AS | Real estate | 2024 |
| Paul M Sælen & Co AS | Wholesale & retail | 2018 |
| Paul M Sælen & Co Holding AS | Wholesale & retail | 2018 |
| Pavillon AS | | 2019 |
| Perestrojka Invest AS | Manufacturing | 2014 |
| Picapoint Studio AS | Professional & scientific | 2008 |
| PK Hægland AS | Real estate | 2005 |
| Pmjo Invest AS | | 2014 |
| Pokenavia AS | Wholesale & retail | 2026 |
| Pondus Holding AS | Real estate | 2005 |
| Porosity AS | | 2015 |
| Postracer Productions AS | Information & communication | 2021 |
| Prebor Invest AS | | 2021 |
| Premium Fish AS | Wholesale & retail | 2023 |
| Present AS | Professional & scientific | 2019 |
| Progmatic AS | Information & communication | 2026 |
| Prosjekt Vest Bolig AS | Real estate | 2016 |
| Prosjekt Vest Bygg AS | Construction | 2021 |
| Prosjekt Vest Holding AS | Construction | 2021 |
| PS Advising Nuf | Professional & scientific | 2010 |
| R H Koldal AS | Real estate | 1995 |
| R O Nydal AS | Construction | 1987 |
| R. Knarvik Holding AS | Administrative & support | 2005 |
| R.Knarvik Eiendom AS | Administrative & support | 2010 |
| Radios SA | Information & communication | 1996 |
| Recursive Oak Holdings AS | | 2025 |
| Regnskapskompetanse AS | Professional & scientific | 2021 |
| Rein Venture AS | | 2019 |
| Reklamehuset Maxprint AS | Professional & scientific | 2025 |
| Reksteren AS | | 2022 |
| Remaco AS | Professional & scientific | 2023 |
| Remme Ventilasjon AS | Construction | 2017 |
| Reng AS | | 2026 |
| Rephi Invest AS | Financial services | 2018 |
| Retro City AS | Professional & scientific | 2025 |
| Rett Mat AS | Wholesale & retail | 2026 |
| RFS Engineering AS | | 2005 |
| RH Byggprosjekt AS | Construction | 2022 |
| Richard Haugland Invest AS | | 2019 |
| Riggservice Vest AS | Manufacturing | 2018 |
| RKT Maskinutleie AS | Administrative & support | 2014 |
| Robe-Invest AS | Financial services | 2017 |
| Rokne Elektro AS | Construction | 2019 |
| Rolfsitt AS | Real estate | 2005 |
| Rothausen Development Norge AS | Information & communication | 2015 |
| Rune Haugland Invest AS | Real estate | 2011 |
| Rune Storum AS | Construction | 2021 |
| Ryp Digital AS | Professional & scientific | 2024 |
| Råheim Service AS | Transport & logistics | 2025 |
| Rød Bygg Og Betong AS | Construction | 2020 |
| Rød Elektro AS | Construction | 2016 |
| Rød Elektro Holding AS | Construction | 2023 |
| Rød-Holding AS | Real estate | 2016 |
| Rørlegger Titlestad AS | Construction | 2021 |
| Rørleggeriet Os AS | Construction | 1997 |
| Rørleggermester Stig E. Nilsen AS | Construction | 2006 |
| S Tvedt AS | Wholesale & retail | 1983 |
| S. Sulen Bygg AS | Construction | 2014 |
| S.Nybø Holding AS | Construction | 2023 |
| S24 Holding AS | Professional & scientific | 2025 |