| Spielführer AS | Professional & scientific | 2021 |
| Spikkestadkvartalene Boligprosjekt AS | Real estate | 2017 |
| Spinderiet Næring AS | Real estate | 2019 |
| Spinell AS | Real estate | 1995 |
| Spinner Kommunikasjon AS | Professional & scientific | 2018 |
| Spinnvill Drammen AS | Arts & recreation | 2020 |
| Sport Invest AS | Wholesale & retail | 2020 |
| Sports Club Akropolis AS | Arts & recreation | 1993 |
| Sportscar AS | Wholesale & retail | 2014 |
| Sportslåven AS | Wholesale & retail | 2020 |
| Sportsveien Holding AS | Real estate | 2023 |
| Sporveien 5 AS | Real estate | 2021 |
| Spring IT Holding AS | | 2026 |
| Sprinklerheat AS | Manufacturing | 2017 |
| Spurv Media AS | Information & communication | 2026 |
| SR Teknikk AS | Wholesale & retail | 1990 |
| SRS Auto AS | Wholesale & retail | 2021 |
| SSC Networks Holding AS | | 2020 |
| SSK AS | Hospitality | 2011 |
| SSS Holding AS | Financial services | 2016 |
| SSW AS | Real estate | 2025 |
| ST Holding AS | Financial services | 1985 |
| ST. Olavsgt. 3 AS | Real estate | 2018 |
| Staalhanske AS | Real estate | 2013 |
| Stabilator AS | Professional & scientific | 2020 |
| Stagecrew AS | Arts & recreation | 2012 |
| Stago Holding AS | | 2021 |
| Stalsbergveien 3 AS | Real estate | 2015 |
| Stamers Rederi AS | Transport & logistics | 1959 |
| Stange Betong AS | Real estate | 1970 |
| Stange Eiendom AS | Real estate | 1986 |
| Stange Gruppen AS | Mining & quarrying | 1985 |
| Star Consult AS | Professional & scientific | 2015 |
| Star Eiendom Ans | Real estate | 1987 |
| Star Næringspark AS | Real estate | 2004 |
| Starte AS | Wholesale & retail | 2019 |
| Startuphuset AS | Real estate | 2020 |
| Starøya Holding AS | | 2021 |
| Stasis Holding AS | | 2025 |
| Stasjonsdrift Hemen Ahmed AS | Wholesale & retail | 2020 |
| Stasjonsenga Eiendom AS | Real estate | 2018 |
| Stasjonsgata 2 Holding AS | Real estate | 2020 |
| Stasjonsgaten 14 AS | Real estate | 2012 |
| Statsaut. Revisor Thormodsrud AS | Professional & scientific | 2013 |
| Stay Sick AS | Financial services | 2015 |
| STD Bygg AS | Construction | 2024 |
| Steb Invest AS | | 2005 |
| Steco Miljø AS | Wholesale & retail | 2000 |
| Steco Nordic AS | Wholesale & retail | 2026 |
| Steco Utleie AS | Administrative & support | 2001 |
| Steconfer AS | Construction | 2024 |
| Steconfer S.A. - Norway Branch Nuf | Construction | 2020 |
| Stecotex AS | Manufacturing | 2020 |
| Steep Invest AS | Professional & scientific | 2022 |
| Stega AS | Health & social care | 2024 |
| Stein Kortvedt AS | Professional & scientific | 2005 |
| Steinberg Handelseiendom AS | Real estate | 2017 |
| Steinbergveien 8 AS | Real estate | 2017 |
| Steiner Solutions AS | Construction | 2024 |
| Steinsfjorden Eiendom AS | Real estate | 2021 |
| Steinsfjorden Eiendom Bolig AS | | 2025 |
| Stellar Kitten Publishing AS | Information & communication | 2024 |
| Sten Gård & Gartneri AS | Agriculture & fishing | 2021 |
| Sten Invest AS | Real estate | 2005 |
| Stener Sørensen Holding AS | Professional & scientific | 1987 |
| Stenseth Konsult AS | Professional & scientific | 2015 |
| Stenseth Mat AS | Wholesale & retail | 1996 |
| Stephan Invest AS | Real estate | 1989 |
| Steplock Norway AS | Professional & scientific | 2018 |
| Stewe AS | Professional & scientific | 2016 |
| Stewe Holding AS | | 2025 |
| Stewe Prosjekt AS | Professional & scientific | 2025 |
| STH Holding AS | Real estate | 2014 |
| Stian R. Invest AS | Construction | 2019 |
| Stifa Invest AS | | 2026 |
| Stifte AS | Professional & scientific | 2022 |
| Stine Berg AS | Wholesale & retail | 2024 |
| Stjerne Bygg Og Eiendom AS | Real estate | 2013 |
| Stjernerør Og Bygg AS | Construction | 2017 |
| Stonje Holding AS | | 2023 |
| Stor-Oslo Regnskap AS | Professional & scientific | 2023 |
| Stordammen Holding AS | Professional & scientific | 2008 |
| Store Saftige Biffer AS | Hospitality | 1997 |
| Stories by Nygård Holding AS | Professional & scientific | 2018 |
| Stories Gruppen AS | Professional & scientific | 2018 |
| Storio AS | Real estate | 2021 |
| Storkjøkkenutvikling AS | Professional & scientific | 1994 |
| Stormoen Gård AS | Real estate | 2023 |
| Stortingsklinikken AS | Health & social care | 2023 |
| Stortingsklinikken Eiendom AS | Real estate | 2021 |
| Stortingsklinikken Offentlig AS | Health & social care | 2022 |
| Strand-Tech AS | Professional & scientific | 2020 |
| Strandgata 12 AS | Real estate | 2015 |
| Strandveien 29 AS | Real estate | 2014 |
| Stratix Consulting AS | Information & communication | 2024 |
| Strax Holding AS | | 2025 |
| Strikkehula AS | Wholesale & retail | 2015 |
| Struktura Bygg AS | Professional & scientific | 2025 |
| Strömsö Kjeveortopedi AS | Health & social care | 2012 |
| Strømmen-Olsen Holding AS | | 2023 |