| SK Eiendomsforvaltning AS | Real estate | 2014 |
| Skargården AS | Real estate | 2025 |
| Skarpsno Elektro AS | Construction | 2004 |
| Skogli Digital AS | Information & communication | 2012 |
| Skumsjøen Hyttegrend AS | Hospitality | 2021 |
| Smaksforum AS | Education | 2023 |
| Smart Tenkt AS | Real estate | 2020 |
| Smedstuen Holding AS | Transport & logistics | 2022 |
| Smedstuen Kran & Transport AS | Transport & logistics | 2023 |
| Smedstuen KT Eiendom AS | Real estate | 2022 |
| Smiua AS | Real estate | 2016 |
| Speedup AS | Education | 2018 |
| Spekeboden AS | Wholesale & retail | 1994 |
| Stars Moelv AS | Hospitality | 2021 |
| Stasjonsdrift Hals AS | Wholesale & retail | 2022 |
| Stasjonsdrift Mangla AS | Administrative & support | 2018 |
| Stein Hesthagen Transport AS | Transport & logistics | 2015 |
| Stein Samdrift Da | Agriculture & fishing | 1998 |
| Steinvik Camping AS | Hospitality | 2002 |
| Steinvik Camping Og Hyttegrend Ans | Real estate | 1991 |
| Stertivegen Vannforsyningsanlegg SA | Water & waste | 2012 |
| Storgata 149 AS | Real estate | 2009 |
| Storgata 78 Moelv AS | Real estate | 2022 |
| Storgata Bruktbil Salg AS | Wholesale & retail | 2021 |
| Storgt. 72 AS | Professional & scientific | 2001 |
| Strand Brænderi AS | Real estate | 2022 |
| Strand Brænderi Eiendom AS | Real estate | 2022 |
| Strand Unikorn AS | Manufacturing | 1974 |
| Strand Unikorn Eiendom 2 AS | Real estate | 2022 |
| Strand Unikorn Eiendom AS | Manufacturing | 1999 |
| Stubbom Holding AS | | 2025 |
| Su Mellom AS | Real estate | 2022 |
| Svarstad Tekstil AS | Wholesale & retail | 2008 |
| Synssenteret Moelv AS | Wholesale & retail | 2012 |
| Taita AS | | 2005 |
| Tannlege Martine Høgset AS | Health & social care | 2023 |
| Tannlegene I Hippegården AS | Health & social care | 2011 |
| Team Sels AS | Wholesale & retail | 2019 |
| The Crown AS | Hospitality | 2018 |
| Tiller Invest AS | Real estate | 2018 |
| Tingvang SA | Real estate | 1957 |
| TMP AS | Professional & scientific | 2021 |
| Tore Skar Holding AS | | 2025 |
| Transportfellesskapet Østlandet AS | Transport & logistics | 1999 |
| Tremas Da | Construction | 2007 |
| Treningssenteret Frisk AS | Arts & recreation | 2005 |
| Trettentretti AS | Real estate | 2020 |
| Trond Bergseth Invest AS | Financial services | 2015 |
| Tømmerterminaler AS | Transport & logistics | 2012 |
| Ugv AS | Professional & scientific | 2025 |
| Uj Trading AB | Manufacturing | 2004 |
| Ulvehiet Holding AS | | 2026 |
| Zecon AS | Professional & scientific | 2023 |
| Økoråd Ringsaker SA | Professional & scientific | 1952 |
| Øss 3 Eiendom AS | Real estate | 2020 |