| Rias-Produkter AS | Agriculture & fishing | 2013 |
| Rindsem Maskinlag SA | Agriculture & fishing | 2013 |
| Rinnan Maskinlag SA | Agriculture & fishing | 1994 |
| Rinnleiret 77 AS | Real estate | 2024 |
| Ritek AS | Other services | 2019 |
| Ritek Eiendom AS | Real estate | 2019 |
| Ritek Holding AS | Other services | 2019 |
| Riwi Maskinlag Da | Agriculture & fishing | 2004 |
| RM Rekkverk AS | Construction | 2022 |
| Rock 'N' Roel AS | | 2022 |
| Roknesvollen 4H-SETER SA | Hospitality | 1993 |
| Roste Holding AS | | 2025 |
| Rune Søberg AS | Financial services | 2014 |
| Røe Holding AS | Manufacturing | 2005 |
| Røe Trevare Coriform AS | Manufacturing | 1987 |
| Rør Og Maling Service AS | Construction | 2026 |
| Røstad Legesenter AS | Health & social care | 2014 |
| Røstad Maskinstasjon SA | Agriculture & fishing | 2012 |
| Røstheim Gartneri AS | Real estate | 2020 |
| S. Skogly AS | Professional & scientific | 2016 |
| Sabrura Levanger AS | Hospitality | 2019 |
| Sakshaug Sport Magneten AS | Wholesale & retail | 1997 |
| Salberg & Svenneby Consult Da | Professional & scientific | 2024 |
| Salong E6 AS | Other services | 1986 |
| Salong Michel Levanger AS | Other services | 1990 |
| Salthammer Nedre Da | Agriculture & fishing | 2016 |
| Samdrifta Ty-Bø Melk Da | Agriculture & fishing | 2003 |
| Sameiet Sjøgt 1 Ans | Real estate | 1989 |
| Sand Auto AS | Wholesale & retail | 2022 |
| Sands Eiendom AS | Real estate | 2018 |
| Sands Holding AS | Real estate | 2018 |
| Sarek AS | Real estate | 2021 |
| Saste Holding AS | | 2025 |
| Saxa 3KANTEN AS | Other services | 2020 |
| SB Invest Levanger AS | Wholesale & retail | 2015 |
| Sebo Boliger AS | Real estate | 2015 |
| Sebo Utleie AS | Real estate | 2022 |
| Selsbakkvegen AS | Real estate | 2015 |
| Selvig Trelast AS | Wholesale & retail | 2000 |
| Semper Digital AS | Information & communication | 2022 |
| Sentrum Eiendom AS | Real estate | 1997 |
| Sentrum Kamiran Frisør AS | Other services | 2018 |
| Sibirica Regnskap AS | Professional & scientific | 2005 |
| Siggi Holding AS | Financial services | 2005 |
| Sipan AS | Professional & scientific | 2003 |
| Sjøbadet Småbåthavn SA | Other services | 1983 |
| Sjøgata 20 AS | Real estate | 2004 |
| Sjøgata 22 Levanger AS | Real estate | 2024 |
| Sjøgt. 3 AS | Real estate | 2022 |
| Skje AS | Real estate | 2013 |
| Skjerve Utvikling AS | Professional & scientific | 2024 |
| Skoleparken 1 AS | Real estate | 2011 |
| Skrøvseth Bygg AS | Construction | 2025 |
| Skrøvseth Eiendom AS | Real estate | 2019 |
| Skånes Maskinlag SA | Agriculture & fishing | 2000 |
| Smak Kreativ Catering AS | Hospitality | 2011 |
| Smart Load AS | Professional & scientific | 2025 |
| Smil Rett Hjem AS | Manufacturing | 2023 |
| Smådyrklinikken Holding AS | Professional & scientific | 2022 |
| Smådyrklinikken Inn-Trøndelag AS | Professional & scientific | 2022 |
| Snuom Psykisk Helse AS | Health & social care | 2019 |
| Sofiegården AS | Hospitality | 2020 |
| Soleada AS | Professional & scientific | 2025 |
| SP Winge Holding AS | | 2026 |
| Spooling AS | | 2026 |
| Sprek Levanger AS | Arts & recreation | 2023 |
| Stakset & Capelli Eiendom AS | Real estate | 1994 |
| Stakset Invest AS | Wholesale & retail | 2005 |
| Stasjonsdrift Rawand AS | Wholesale & retail | 2023 |
| Staupslia 34 AS | Real estate | 2025 |
| Staupslia Eiendom AS | Real estate | 2020 |
| Staupslia Hagesenter AS | Agriculture & fishing | 2001 |
| Stayer AS | Information & communication | 2025 |
| Stedi AS | Wholesale & retail | 2021 |
| Stedi Utvikling AS | Professional & scientific | 2021 |
| Steen Betongpumping AS | Transport & logistics | 1997 |
| Steen Eiendom AS | Real estate | 2003 |
| Steinkjer Invest AS | Manufacturing | 2022 |
| Stenes Holding AS | Real estate | 1999 |
| Stian Lein Transport AS | Transport & logistics | 2023 |
| Stian Skjelbred AS | Information & communication | 2015 |
| Stiftsstaden Eiendom AS | Real estate | 2018 |
| Stiklestad Eiendom AS | Real estate | 2002 |
| Stiklestad Eiendom Geitingsvolden AS | Real estate | 2022 |
| Stiklestad Eiendom Kvislaparken AS | Real estate | 2020 |
| Stiklestad Eiendom Namsos AS | Real estate | 2020 |
| Stiklestad Eiendom Nestvold AS | Construction | 2019 |
| Stiklestad Eiendom Nordgata AS | Construction | 2016 |
| Stiklestad Eiendom Prosjekt AS | Real estate | 2022 |
| Stiklestad Eiendom Sjøgata AS | Real estate | 2022 |
| Stiklestad Eiendom Utbygging AS | Real estate | 2022 |
| Stiklestad Hotell Eiendom AS | Real estate | 2006 |
| Stofflund AS | Other services | 2020 |
| Strandhaugvegen Utvikling AS | Real estate | 2019 |
| Strandstind AS | Education | 2023 |
| Strandveien 7 Utbygging AS | Real estate | 2016 |
| Strømsøegården AS | Hospitality | 1987 |
| Styrk Fysioterapi AS | Health & social care | 2013 |
| Støra Eiendom AS | Real estate | 2014 |
| Sundal Drift AS | Hospitality | 2026 |