| Simen Uhlen Holding AS | Construction | 2008 |
| Siris Biofotonterapi AS | Health & social care | 2013 |
| Siv.Ing Kjell Gurigard AS | Professional & scientific | 2005 |
| Sivilingeniør Nils Rømoen AS | Professional & scientific | 2007 |
| Six AS | Arts & recreation | 2023 |
| Sjodalen Fjellgrend AS | Real estate | 2013 |
| Sjodalen Fjellgrend Entreprenør AS | Real estate | 2015 |
| Sjodalen Infra AS | Real estate | 2016 |
| Skaansar Holding AS | Real estate | 2005 |
| Skaarz AS | Arts & recreation | 2022 |
| Skaarz Holding AS | Real estate | 2022 |
| Skarpsno AS | Real estate | 1998 |
| Skarpsno Bolig AS | Real estate | 2017 |
| Skarpsno Mesna AS | Real estate | 2003 |
| Skarpsno Stenumgård AS | Real estate | 2017 |
| Skarpsno Søbakken AS | Real estate | 2017 |
| Skeidar Lillehammer AS | Wholesale & retail | 1997 |
| Skeiekongen AS | Professional & scientific | 2021 |
| Skeiporten AS | Real estate | 2019 |
| Skirious Problems AS | Information & communication | 2026 |
| Skjeggestad Dale AS | Professional & scientific | 2019 |
| Skjerping Byggservice AS | Construction | 2024 |
| Skjerping Holding AS | | 2026 |
| Skogli Eiendom AS | Real estate | 1999 |
| Skogli Helse Og Rehabiliteringssenter AS | Health & social care | 1999 |
| Skogmo Holding AS | | 2020 |
| Skoleconsult Ans | Professional & scientific | 2001 |
| Skoletorget 8 AS | Wholesale & retail | 2012 |
| Skoletorget Garasjebygg SA | Real estate | 1955 |
| Skottevig Invest 2 AS | | 2021 |
| Skottevig Invest AS | Financial services | 2014 |
| Skurva Invest AS | Financial services | 2011 |
| Skyhøi AS | Education | 2023 |
| Skyttermoen Hsi AS | Real estate | 2019 |
| Sletmoen Holding AS | | 2019 |
| Sliteneliten Da | Arts & recreation | 2021 |
| Smallville AS | Information & communication | 2014 |
| Smallville Films AS | Information & communication | 2016 |
| Smartski Technologies AS | Professional & scientific | 2012 |
| Smedås Utvikling AS | Education | 2024 |
| Smek Holding AS | | 2020 |
| Smek Holding II AS | | 2025 |
| Smestad Frisør AS | Other services | 2012 |
| Smi AS | Real estate | 1990 |
| Smidesang Eiendom AS | | 1965 |
| Snaks AS | Information & communication | 2026 |
| Snekkerlaget AS | Construction | 2014 |
| Snekkerstuvarpet Invest AS | | 2025 |
| Snekkervegen 4 AS | Real estate | 2025 |
| Snekkerveien 1 AS | Real estate | 2014 |
| Snos Lillehammer AS | Wholesale & retail | 2026 |
| Snos Strandtorget AS | Wholesale & retail | 2019 |
| Snø Eiendom AS | Real estate | 2021 |
| Snøhetta Invest AS | Real estate | 2008 |
| Snøkrystallen Trykkeri Og Reklame AS | Manufacturing | 2024 |
| So-Bygg AS | Construction | 2021 |
| Solheimsvegen 3 AS | Real estate | 2022 |
| Solhøgda Eiendom AS | Real estate | 2015 |
| Sollien Invest AS | | 2024 |
| Solstein Gruppen AS | Construction | 2021 |
| Solstein Infra AS | Construction | 2025 |
| Solveggen Eiendom AS | Real estate | 2025 |
| Solveggen Invest AS | | 2023 |
| Somco AS | Wholesale & retail | 2005 |
| Sorgenfri Lillehammer AS | Hospitality | 2020 |
| Sparsmak AS | Manufacturing | 2025 |
| Spekedalen/Sølendalen Fiskeadministrasjon | Arts & recreation | 2005 |
| Speku AS | | 2024 |
| Spillorama Lillehammer AS | Arts & recreation | 2010 |
| Spiria AS | Education | 2019 |
| Sport 1 Strandtorget AS | Wholesale & retail | 2010 |
| Sport Analytics Innovation AS | Professional & scientific | 2024 |
| Sportline Ans | Wholesale & retail | 1997 |
| SR Byggprosjekt AS | Real estate | 2019 |
| ST Dalby AS | Construction | 2021 |
| Stampa AS | Real estate | 2022 |
| Stampa Eiendom AS | Real estate | 2018 |
| Stappmætt AS | Hospitality | 2024 |
| Stasjonsdrift Jarmann Larsen AS | Wholesale & retail | 2019 |
| Steifo AS | Real estate | 2015 |
| Steinstad Holding AS | | 2015 |
| Stenbakk Invest AS | | 2021 |
| Stensby Helse AS | Health & social care | 2023 |
| Stensrud AS | Wholesale & retail | 1976 |
| Steve 351 Holding AS | | 2023 |
| Stian Lunn Holding AS | | 2026 |
| Stig Og Stein Studio AS | Information & communication | 2018 |
| Sting Studio AS | Professional & scientific | 2022 |
| Stinterud AS | | 2025 |
| Storbrofoss Kraftanlegg Da | Energy | 1999 |
| Storgata 107 Eiendom AS | Real estate | 2023 |
| Storgata 121 AS | Real estate | 2016 |
| Storgata 178 AS | Real estate | 2016 |
| Storgata 36B AS | Real estate | 2020 |
| Storgata 37 Nybygg AS | Real estate | 2024 |
| Storgata 38 Lillehammer AS | Real estate | 2025 |
| Storgata 55 Lillehammer AS | Real estate | 2011 |
| Storgata 65 Lillehammer Ans | Real estate | 2002 |
| Storgata 79 Lillehammer Ans | Real estate | 2003 |
| Storgata 81 AS | Real estate | 2020 |