| Mobil Eiendom AS | Real estate | 2011 |
| Monicas Salong AS | Other services | 2016 |
| Mood Interiørarkitekter AS | Professional & scientific | 2007 |
| Moseid Gård AS | Agriculture & fishing | 2025 |
| Moseidmoen Bolig AS | Real estate | 2017 |
| Moseidmoen Industri AS | Real estate | 2017 |
| Moseidmoen Industri II AS | Real estate | 2017 |
| Moseidmoen Industribygg AS | Real estate | 2002 |
| Mpay AS | Information & communication | 2012 |
| Multiservice Vennesla AS | Administrative & support | 2023 |
| Murmester PM AS | Construction | 2024 |
| Murmesterfirma Høiåsen AS | Construction | 2007 |
| Myre & Partnere AS | Financial services | 2010 |
| Mønsted Holding AS | Real estate | 2009 |
| Nettkroken AS | Information & communication | 1999 |
| New Style Frisør AS | Other services | 2017 |
| Newstep AS | Health & social care | 2013 |
| Nextnor AS | Professional & scientific | 2016 |
| Nilsen Investment AS | | 2026 |
| Nipedal Tak Og Membran AS | Construction | 2023 |
| Nira AS | Financial services | 2005 |
| Nordlo Vennesla AS | Wholesale & retail | 1977 |
| Norgesplaster AS | Manufacturing | 2010 |
| Norseating AS | Manufacturing | 2022 |
| Nybruktbil AS | Wholesale & retail | 2022 |
| Nye Øyesletta Eiendom AS | Real estate | 2025 |
| Nystøl Prosjekt AS | Real estate | 2006 |
| Nærings Invest AS | Administrative & support | 2013 |
| O. H. Eiendom AS | Financial services | 2005 |
| Oaa Holding AS | Other services | 2015 |
| Oasen Skole Vennesla AS | Education | 2017 |
| Okt Invest AS | Professional & scientific | 2006 |
| OKV8 Eiendom AS | Real estate | 2021 |
| Ol to VVS AS | Construction | 2001 |
| Olaf Aas AS | Administrative & support | 1945 |
| Ole Fjermedal Holding AS | Construction | 2013 |
| Ole Fjermedal Invest AS | | 2025 |
| Olto Varmepumpeservice AS | Construction | 2015 |
| Omdal-Invest AS | Real estate | 2018 |
| Omestad Og Eidet Montasje AS | Construction | 2022 |
| Omnino AS | Arts & recreation | 2021 |
| Otc Eiendom AS | Real estate | 2025 |
| Otra Eiendomsutvikling AS | Real estate | 2017 |
| Otra Forsikring AS | Financial services | 2022 |
| Otrahus AS | Real estate | 2017 |
| Otraparken AS | Real estate | 2005 |
| Otraparken Bolig AS | Real estate | 2022 |
| Otraparken Bolig Kjøpesenter AS | Real estate | 2022 |
| Otrasvingen 1 AS | Financial services | 2005 |
| Otredal AS | Real estate | 2015 |
| Ovn Holding AS | Real estate | 2021 |
| P.F Invest AS | Real estate | 2023 |
| Padel Vennesla AS | Arts & recreation | 2022 |
| PBJ Entreprenør AS | Administrative & support | 2022 |
| Pipefiks AS | Construction | 2014 |
| Pisi Holding AS | Wholesale & retail | 2021 |
| Plantasjen Eiendom Nedre Eiker AS | Real estate | 2003 |
| Plantasjen Eiendom Skien AS | Real estate | 2004 |
| PMV Mur Og Flis AS | Construction | 2014 |
| Poi Eiendom AS | Real estate | 2008 |
| Poi Holding AS | Real estate | 2008 |
| Postgården Vennesla AS | Real estate | 2002 |
| Procon Eiendom AS | Real estate | 1994 |
| PSH Holding AS | Professional & scientific | 2020 |
| QB Møbler AS | Wholesale & retail | 2025 |
| Quick Clean AS | Real estate | 2010 |
| R.L Eiendom AS | Real estate | 2022 |
| Radio Loland SA | Information & communication | 1988 |
| Raglamyra Eiendom AS | Real estate | 2006 |
| Rauarmonen Holding AS | | 2020 |
| Regen AS | Professional & scientific | 2022 |
| Reklamehuset AS | Professional & scientific | 2017 |
| Reko Regnskap & Økonomi AS | Professional & scientific | 1998 |
| Rem Holding AS | Real estate | 2017 |
| Revia Holding AS | Real estate | 2020 |
| Riba Kristiansand Holding AS | | 2005 |
| RK & Crue AS | Construction | 2020 |
| RL Holding AS | Real estate | 2005 |
| Rlindgren Invest AS | Real estate | 2025 |
| RLS Holding AS | Real estate | 2016 |
| RN Multiservice AS | Construction | 2022 |
| Roka Eiendom AS | Real estate | 2017 |
| Rolfs Alt Mulig AS | Wholesale & retail | 2014 |
| Rosaas Holding AS | Real estate | 2026 |
| Rossevatnmma AS | Arts & recreation | 2026 |
| Royal Sushi Vennesla AS | Hospitality | 2022 |
| RST Eiendom AS | Real estate | 2021 |
| Rubendahl Consulting AS | Information & communication | 2011 |
| Ruenes Holding AS | Real estate | 2017 |
| Ruhaven AS | | 2025 |
| Rune & Arvids Caravan Ans | Other services | 1994 |
| Rymo AS | Real estate | 2014 |
| Røinås Skogsdrift AS | Agriculture & fishing | 2025 |
| Rør Eksperten AS | Construction | 2022 |
| Safe Inflator AS | Professional & scientific | 2016 |
| Sakko AS | Information & communication | 2019 |
| Salong Head on AS | Other services | 2017 |
| Salongsilhouette AS | Other services | 2015 |
| Samtech AS | Wholesale & retail | 1997 |
| Sand On/Offshore Service AS | Professional & scientific | 2022 |