| Sass Logistics PL Norway Nuf | Transport & logistics | 2021 |
| Sass Logistics Ro Norway Nuf | Transport & logistics | 2018 |
| Savonette AS | | 2024 |
| SB Gruppen AS | Transport & logistics | 2019 |
| Scaff Holding AS | | 2023 |
| Scandigen Lab AS | Professional & scientific | 2021 |
| Scandimport AS | Wholesale & retail | 2025 |
| Schjølberg & Tombre Eiendom AS | Real estate | 2010 |
| Schønberg Kolonial AS | Wholesale & retail | 2021 |
| SE Eiendom-Invest AS | Real estate | 1987 |
| Security Invest AS | Information & communication | 2008 |
| Sekvens AS | Professional & scientific | 2023 |
| Sekvens Holding AS | Professional & scientific | 2023 |
| Selcas AS | | 2015 |
| Sellanrå Invest AS | Financial services | 2015 |
| Selvesterobin AS | | 2013 |
| Seminargata 3 AS | Real estate | 2025 |
| Senil Invest AS | | 2020 |
| Sentrum Bilpleie Hamar AS | Other services | 2025 |
| Sentrum Fotklinikk AS | Other services | 2013 |
| Sentrumskvartalene AS | Real estate | 1974 |
| Serrianne AS | Health & social care | 2012 |
| Servicesentret AS | Other services | 1984 |
| Seterløkka Bjørkenga Tomt AS | Real estate | 2025 |
| Seterløkka Boliger AS | Real estate | 2024 |
| Settebo AS | Real estate | 2025 |
| SGS Norway AS | Professional & scientific | 1999 |
| Sha Prosjekt AS | Manufacturing | 1997 |
| Sham Dagligvare AS | Wholesale & retail | 2021 |
| Shellsons AS | | 2019 |
| Shikau Afro Frisør Salong AS | Other services | 2023 |
| Shiuz AS | | 2026 |
| Sicaro AS | Administrative & support | 2023 |
| Sidewind AS | Real estate | 2023 |
| Siesta Lunchbar AS | Hospitality | 2018 |
| Siga Barneklær AS | Wholesale & retail | 2004 |
| Signal Og Sikringsteknikk AS | Professional & scientific | 2013 |
| Sigra Invest AS | | 2025 |
| Silkyway Da | Wholesale & retail | 2016 |
| Silva Bolig AS | Construction | 2024 |
| Silva Bolig Prosjekt AS | Real estate | 2024 |
| Silver Willow Invest AS | Financial services | 2013 |
| Simbra Rådgivning AS | Professional & scientific | 2019 |
| Simen Øian Gjermundsen AS | Information & communication | 2018 |
| Sin Sans Senza AS | Wholesale & retail | 2025 |
| Sina Invest AS | | 2007 |
| Sindre Risheim Design AS | Professional & scientific | 2026 |
| Sivil Ingeniør Marius Bakken AS | Professional & scientific | 2022 |
| Sivilingeniør Asbjørn Andersen Byggrådgivning AS | Professional & scientific | 2017 |
| Sjur Rønn Sætre Holding AS | Real estate | 2026 |
| Sjøfront Drift AS | Real estate | 2021 |
| Skaret Graving AS | Construction | 2015 |
| Skeidar Hamar AS | Wholesale & retail | 1998 |
| Skeiderud Kapital AS | | 2025 |
| Skidata Scandinavia AB Nuf | Information & communication | 1995 |
| Skifter AS | Transport & logistics | 2024 |
| Skin Essence Hamar AS | Other services | 2024 |
| Skinco AS | Other services | 2022 |
| SKJENK2317 AS | Hospitality | 2022 |
| Skjærheld AS | | 2026 |
| Skjævelandsbrunå AS | Real estate | 2022 |
| Skogsrudjordet AS | Real estate | 2011 |
| Skolehotell AS | Information & communication | 2026 |
| Skotexnæs AS | Wholesale & retail | 1975 |
| Skrivekraft AS | Arts & recreation | 2020 |
| Skåja AS | | 2025 |
| Skårholen AS | | 2021 |
| Skøyern Kiosk AS | Wholesale & retail | 2014 |
| Slettefjell Vind Da | Energy | 2026 |
| Slåttsveen I AS | Wholesale & retail | 2012 |
| Slåttsveen II AS | Information & communication | 2014 |
| Slåttsveen III AS | Wholesale & retail | 2000 |
| SM Drift AS | Administrative & support | 2026 |
| Smart Cognition AS | Information & communication | 2017 |
| Smart Lifestyle AS | Information & communication | 2022 |
| Smeby Eiendom AS | Real estate | 2018 |
| Smeby Familiebarnehage Da | Education | 1995 |
| Smeby Invest AS | Real estate | 2019 |
| Smebyhjørnet Eiendom AS | Real estate | 2013 |
| Smertebehandling AS | Health & social care | 2008 |
| SMG Invest AS | | 2020 |
| SN Samleren AS | Real estate | 2005 |
| Snarud Invest AS | Financial services | 2024 |
| Sniper AS | Real estate | 2000 |
| Sno Prosjektutvikling AS | Professional & scientific | 2025 |
| Snow Leaf Studios AS | Information & communication | 2021 |
| Soel Holding AS | Real estate | 2017 |
| Sol & Tom AS | Wholesale & retail | 2022 |
| Solar Brumunddal AS | Wholesale & retail | 1995 |
| Solstua Holding AS | | 2025 |
| Sommervold Holding AS | Other services | 2021 |
| Soriamoria AS | Real estate | 2025 |
| Spanstind Invest AS | Real estate | 2016 |
| Sparebank 1 Finans Østlandet AS | Financial services | 1995 |
| Sparebank 1 Forretningspartner Østlandet AS | Professional & scientific | 1993 |
| Sparebank 1 Mobilitet Holding AS | | 2021 |
| Sparebank 1 Østlandet | Financial services | 1988 |
| Sparebank 1 Østlandet Verdigjenvinning AS | | 2021 |
| Spectra Norge AS | Wholesale & retail | 1995 |
| Speed Experience AS | Arts & recreation | 2018 |