| Sol-Berg Holding AS | Real estate | 2015 |
| Solbakken 1 AS | | 2020 |
| Solid App AS | Information & communication | 2015 |
| Sommerrovegen 3 AS | Real estate | 2021 |
| Sommerroveien 7 AS | Real estate | 1981 |
| Sonima Invest AS | | 2025 |
| Spartan Holding AS | | 2026 |
| Speil Holding AS | Real estate | 2015 |
| Spektralion AS | Information & communication | 2021 |
| Spilsberg Skog Ans | Real estate | 2001 |
| Spiro S.A. | Transport & logistics | 2002 |
| Spirus AS | Professional & scientific | 2005 |
| Squishy AS | Wholesale & retail | 2024 |
| Sre Invest AS | Real estate | 2010 |
| SSM Industrier AS | Real estate | 2005 |
| Sstk Da | Wholesale & retail | 2024 |
| Stag Holding AS | | 2023 |
| Stagerent AS | Arts & recreation | 2023 |
| Stampevegen 1 AS | Real estate | 2014 |
| Star Malerservice AS | Construction | 2015 |
| Stas Nytorvet AS | Real estate | 2023 |
| Stasjonsvegen 7 Og 9 Eiendom AS | Real estate | 2005 |
| Stasjonsvegen 7 Og 9 Næring AS | Real estate | 2025 |
| Stasjonsveien 3A Og 5A Ans | Real estate | 2004 |
| Steady Floating AS | | 2017 |
| Steen Begravelsesbyrå AS | Other services | 2023 |
| Stende S Eiendomsselskap AS | Real estate | 2018 |
| Stig Og Arilds AS | Administrative & support | 2017 |
| Stinsa AS | | 2008 |
| Stolvstadlia Utvikling AS | Real estate | 2018 |
| Storg 12 AS | Real estate | 1993 |
| Storgata 123 Dokka AS | Real estate | 2021 |
| Storgata 125 Dokka AS | Real estate | 2021 |
| Storgata 130-132 Moelv AS | Real estate | 2018 |
| Storgata 23 Gjøvik AS | Real estate | 2021 |
| Storgata 24-26 AS | Real estate | 2006 |
| Storgata 25 Gjøvik AS | Real estate | 2011 |
| Storgata 40 Ans | Real estate | 2002 |
| Storgata 41 Lillehammer AS | Real estate | 2019 |
| Storgata 6 Elverum AS | Real estate | 1972 |
| Storgata 6 Gjøvik AS | Real estate | 2020 |
| Storgata 9 Gjøvik AS | Real estate | 2017 |
| Storgata Edge Utvikling AS | Real estate | 2020 |
| Storgaten Fysioterapi Da | Health & social care | 1998 |
| Storgrana AS | Professional & scientific | 2026 |
| Storm Adventures AS | Administrative & support | 2020 |
| Storm Adventures Holding AS | Administrative & support | 2020 |
| Storm IT Sikkerhet AS | Information & communication | 2025 |
| Storquizen AS | Arts & recreation | 2015 |
| Storyspellcanvas Ans | Arts & recreation | 2024 |
| STR Media AS | Arts & recreation | 2020 |
| Strand Gjøvik AS | Hospitality | 2005 |
| Strand Nilsen Kiropraktikk AS | Health & social care | 2023 |
| Stranda Eiendom AS | Real estate | 1997 |
| Strandgata 16 Gjøvik AS | Real estate | 2009 |
| Strandgata 38 Gjøvik AS | Real estate | 2021 |
| Strandgaten 17 Gjøvik AS | Real estate | 2016 |
| Strandvegen 10A Brumunddal AS | Real estate | 2025 |
| Strandvegen 12 Utvikling AS | Real estate | 2021 |
| Stratocaster AS | Real estate | 2014 |
| Stridsklev Butikkeiendom AS | Real estate | 2018 |
| Studentboliger Gjøvik Campus AS | Real estate | 2015 |
| Studio B3 AS | Information & communication | 2025 |
| Studio Cec AS | Professional & scientific | 2025 |
| Studio Sisko AS | Wholesale & retail | 1997 |
| Sulland Gjøvik AS | Other services | 1997 |
| Sulland Holding AS | Other services | 2005 |
| Svahnen AS | Professional & scientific | 2026 |
| Svanen Service AS | Administrative & support | 2016 |
| Svarteputten Holding AS | Financial services | 2005 |
| Svasti Holding AS | Construction | 2021 |
| Sveen Administrasjon AS | Professional & scientific | 2022 |
| Sveen Elektro AS | Construction | 2013 |
| Svein Hage Holding AS | Financial services | 2015 |
| Sven Strøm AS | Financial services | 2005 |
| Sveum & Co AS | Wholesale & retail | 2024 |
| Sveum Byggdesign AS | Professional & scientific | 2025 |
| Sveum Eiendom AS | Real estate | 2003 |
| Sveum Fryseri AS | Transport & logistics | 1985 |
| Svingen Lounge AS | Real estate | 2024 |
| Sviund Transport AS | Transport & logistics | 2025 |
| Svømmepakken AS | Wholesale & retail | 2022 |
| SW Media Ans | Information & communication | 2025 |
| Syglekugle AS | | 2025 |
| Syljuåsen AS | Construction | 2001 |
| Syljuåsen Eiendom AS | Real estate | 2022 |
| Syljuåsen Gruppen AS | Professional & scientific | 2004 |
| Syljuåsen Holding AS | Real estate | 2005 |
| Syljuåsen Invest AS | Construction | 2022 |
| Synsenteret AS | Wholesale & retail | 1989 |
| Synstelien Holding AS | | 2025 |
| System-Tre Gjøvik AS | Real estate | 1976 |
| Systemro AS | | 2026 |
| Skattum Eiendom A/S | Real estate | 1970 |
| Strique & Mique A/S | Wholesale & retail | 1988 |
| Sønes Eiendom AS | Real estate | 2022 |
| Sønes Holding AS | Real estate | 2022 |
| Sønes Mur Og Flis AS | Construction | 2025 |
| Sørbyen Barnehage AS | Education | 2016 |
| Sørbyen Eiendom Ans | Real estate | 1998 |