| Skaiti Ans | Agriculture & fishing | 2022 |
| Skansen Auto AS | Wholesale & retail | 2009 |
| Skansen Motor AS | Wholesale & retail | 2024 |
| Skarstein Bygg AS | Construction | 2014 |
| Skarstein Holding AS | Construction | 2019 |
| Skidoo Senteret AS | Wholesale & retail | 2022 |
| Skillemo Eiendom AS | Real estate | 2022 |
| Skimos Eiendom AS | Construction | 2019 |
| Skipp AS | Information & communication | 2025 |
| Skippertorget 2 Og 4 AS | Real estate | 2008 |
| Skogheim Solutions AS | Transport & logistics | 2024 |
| Skogmo Boliger AS | Construction | 2020 |
| Skohuset Laila AS | Wholesale & retail | 1998 |
| Skorpens Bakeri & Konditori AS | Real estate | 2002 |
| Skrattejakt AS | Administrative & support | 2019 |
| Skír Energy AS | Professional & scientific | 2025 |
| SM Roxrud AS | | 2026 |
| Sm-Holding AS | Mining & quarrying | 2008 |
| Smaken Av Finnmark AS | Agriculture & fishing | 2015 |
| Smartdok AS | Information & communication | 2005 |
| Smarter Energy AS | Professional & scientific | 2022 |
| Smarter Security AS | Administrative & support | 2021 |
| Smedgjerdet AS | Real estate | 2013 |
| Smia Eiendom Alta AS | Real estate | 2004 |
| Smibakken Holding AS | | 2024 |
| Smolt Holding AS | Professional & scientific | 1997 |
| Små&Søte AS | Wholesale & retail | 2025 |
| SN Holding Alta AS | Construction | 2018 |
| SN Maskin AS | Construction | 2022 |
| Snefjord Holding AS | | 2022 |
| Snehvit Barnehage AS | Education | 1990 |
| Snekker Gunes AS | Construction | 2013 |
| So Holding Og Invest AS | Construction | 2019 |
| Sol Utvikling AS | Real estate | 2025 |
| Solid VVS AS | Construction | 2026 |
| Solnesset Boliger AS | Real estate | 2025 |
| Solno AS | | 2023 |
| Solsletta Gård Ans | Agriculture & fishing | 1985 |
| Solsletten Nord AS | Wholesale & retail | 2005 |
| Solutions Invest THK AS | Financial services | 2017 |
| Solvang Camping Og Leirsted AS | Hospitality | 2020 |
| Sommarnes Fisk AS | Agriculture & fishing | 2022 |
| Sommarnes Holding AS | | 2022 |
| Sondre Holding AS | Agriculture & fishing | 2020 |
| Sophie Invest AS | | 2023 |
| Soreng AS | Information & communication | 2023 |
| Soreng Holding AS | Information & communication | 2023 |
| Sorenskriverveien 34 AS | Real estate | 2023 |
| Sorrisniva AS | Arts & recreation | 1991 |
| Spenst Alta AS | Arts & recreation | 2000 |
| Spenst Alta Holding AS | Arts & recreation | 2005 |
| Sport 1 Alta AS | Wholesale & retail | 2009 |
| Sprosseverkstedet Da | Manufacturing | 1997 |
| SSK Utleie AS | Administrative & support | 2021 |
| ST Maskinutleie AS | Real estate | 2022 |
| St.Tropez Alta Ans | Arts & recreation | 2004 |
| Staffen Holding AS | Information & communication | 2023 |
| Stasjonsdrift Bjerring AS | Wholesale & retail | 2026 |
| Stefanussen Hansen AS | Professional & scientific | 2026 |
| Stefanussen Hansen Holding AS | | 2026 |
| Stein Design AS | Wholesale & retail | 1997 |
| Stein Design Skifer AS | Wholesale & retail | 2011 |
| Steinfoss AS | | 2018 |
| Steinwahl AS | Other services | 2020 |
| Stengelsen Husky AS | Administrative & support | 2019 |
| Stian Ingebrigtsen Holding AS | Agriculture & fishing | 2008 |
| Stian Nilsen Invest AS | Financial services | 2018 |
| Stian Olsen Eiendom AS | Real estate | 2022 |
| Stian Olsen Holding AS | Administrative & support | 2022 |
| Stibi AS | Construction | 2018 |
| Stig Brose AS | Professional & scientific | 2023 |
| Stigs Bud AS | Transport & logistics | 2016 |
| Stilla Holding AS | Other services | 2018 |
| Stjernegrillen Alta AS | Hospitality | 2021 |
| Stjomo AS | Construction | 2022 |
| Storelva Nord AS | Real estate | 2024 |
| Storeng Holding AS | Real estate | 2021 |
| Storengveien 21 AS | Real estate | 2021 |
| Storengveien 26 AS | Real estate | 2021 |
| Storengveien 27 AS | Real estate | 2025 |
| Storgata 11-13 Honningsvåg AS | Real estate | 2018 |
| Stranddalen Sand AS | Mining & quarrying | 2006 |
| Strandgata 4 AS | Real estate | 1991 |
| Strandgata Handelseiendom AS | Real estate | 2026 |
| Strifeldts Transport AS | Transport & logistics | 1990 |
| Stritrans AS | Transport & logistics | 2005 |
| Strå by Nyvoll AS | Other services | 2022 |
| Strøm Holding AS | Professional & scientific | 2024 |
| Strøm Invest AS | Real estate | 1968 |
| Strøm Media AS | Professional & scientific | 2024 |
| Stål Og Gummi AS | Wholesale & retail | 2016 |
| Stål Og Gummi Eiendom AS | Real estate | 1984 |
| Stålnakke AS | Professional & scientific | 2013 |
| Sub 12 AS | Hospitality | 2022 |
| Suhr AS | Construction | 2024 |
| Sulland Bilsenter Alta AS | Wholesale & retail | 2025 |
| Sundstrøm Eiendom AS | Real estate | 2019 |
| Sundstrøm Holding AS | Construction | 2019 |
| Sushi Point Alta AS | Hospitality | 2020 |
| Svartskog Holding AS | Real estate | 2021 |