| Ribe Rental AS | Administrative & support | 2020 |
| Ripple Invest AS | | 2025 |
| Rislå Samdrift Da | Agriculture & fishing | 2001 |
| Rm-C Engineering | Professional & scientific | 2013 |
| Ronneseth Holding AS | | 2021 |
| Rose Premium Invest AS | | 2021 |
| Round Robin AS | | 2017 |
| Rune Blix Holding AS | Construction | 2006 |
| Rune Jortveit AS | Information & communication | 2007 |
| Rønnevig Bygg AS | Construction | 2012 |
| Rørhus AS | Real estate | 1987 |
| Rørlegger Modalen AS | Construction | 2019 |
| Rørlegger Olav Skuggevik AS | Construction | 2009 |
| Røysland Bygg AS | Construction | 2010 |
| S.G.M Eiendom AS | Real estate | 2010 |
| Saac Holding AS | Real estate | 2003 |
| Saint-Gobain Matériaux Céramiques Benelux SA | Manufacturing | 2004 |
| Sale Clean Master AS | Administrative & support | 2026 |
| Salis Bedriftshelsetjeneste AS | Health & social care | 2001 |
| Salongen Lillesand Da | Administrative & support | 2023 |
| Salongen Vår AS | Other services | 1993 |
| Saltvik Utvikling AS | | 2005 |
| Sanden Invest AS | | 2017 |
| Sanden Ship Invest AS | Transport & logistics | 2023 |
| Sanden Trafikkskole AS | Education | 2022 |
| Sanden Transport AS | Water & waste | 2019 |
| Sandsgabet AS | Real estate | 2015 |
| Sandvad Eiendom AS | Real estate | 2009 |
| Sandvad Eiendom Vest AS | Real estate | 2024 |
| Sangereid AS | Real estate | 2013 |
| Satono Invest AS | Wholesale & retail | 2005 |
| SBR Invest AS | Real estate | 2005 |
| Schenk Utleie AS | Administrative & support | 2013 |
| Schjelderup Trondahl Arkitekter AS | Professional & scientific | 2009 |
| Seawind Consulting AS | Professional & scientific | 2023 |
| Sekkebekksletta 2 AS | Real estate | 2013 |
| Senterveien 4 Eiendom AS | Real estate | 2014 |
| Sentrumsgården AS | Real estate | 1986 |
| Service Sør AS | Other services | 2018 |
| SG Armaturen AS | Manufacturing | 1990 |
| SG Armaturen Holding AS | | 2021 |
| SG Holding I AS | Financial services | 2004 |
| SG Holding II AS | Real estate | 2004 |
| SGL Invest AS | Real estate | 2005 |
| SH - Elektro AS | Construction | 2009 |
| Shabr AS | | 2020 |
| Shiny Holding AS | Information & communication | 2021 |
| Ships Holding AS | Financial services | 2016 |
| Signe Ann Jørgensen AS | Professional & scientific | 2022 |
| Sipo AS | Wholesale & retail | 2024 |
| Sirius Labs AS | Arts & recreation | 2015 |
| Sirnes Consulting AS | Professional & scientific | 2020 |
| Sivilarkitekt Gunnar Knutsen AS | Professional & scientific | 1997 |
| Sivilarkitekt Knut Haarklau AS | Professional & scientific | 2021 |
| Sivilarkitekt Løvdahl AS | Professional & scientific | 1996 |
| Sjettesporet AS | Professional & scientific | 2026 |
| Skagerak Solutions AS | Professional & scientific | 2020 |
| Skalle & Øina Håndtverk AS | Construction | 2023 |
| Skeie Agri AS | Agriculture & fishing | 2018 |
| Skibsaksjeselskapet Haasund AS | Transport & logistics | 2016 |
| Skifjell Invest AS | Real estate | 2011 |
| Skipperheia Vann- Og Avløpslag SA | Water & waste | 2014 |
| Skipsknatten AS | Construction | 2012 |
| Skolegata 2 AS | Real estate | 2013 |
| Skuggevik Gård AS | Real estate | 2015 |
| Skuggevik Utvikling AS | Real estate | 2013 |
| Sky Fitness Lillesand AS | Arts & recreation | 2019 |
| Skytterheia AS | Construction | 2017 |
| Smartmur AS | Wholesale & retail | 2021 |
| Smeigedag Sauna AS | Other services | 2024 |
| Smith Petersens GT. 2 AS | Real estate | 2022 |
| Småverk AS | Wholesale & retail | 2026 |
| Solborg Utvikling AS | Real estate | 2013 |
| Sole Marine Services AS | Professional & scientific | 2016 |
| Sole Shipping AS | Transport & logistics | 2004 |
| Solflaten AS | Real estate | 2000 |
| Solsiden 3 AS | Arts & recreation | 2022 |
| Solsletta Holding AS | Manufacturing | 2013 |
| Solstranda Mur AS | Administrative & support | 2022 |
| Solveit AS | Information & communication | 2025 |
| Sommervegen 9 AS | Real estate | 2016 |
| Sorified AS | | 2022 |
| Spring Marketing AS | Professional & scientific | 2024 |
| Spritt Holding AS | | 2025 |
| Storemyr Dyreklinikk AS | Professional & scientific | 2021 |
| Storemyr Holding AS | | 2022 |
| Storemyr Næringspark AS | Real estate | 2005 |
| Storemyrlia Lager AS | Real estate | 2021 |
| Storemyrsletta 2 AS | Other services | 1987 |
| Storgaten 5 AS | Real estate | 2025 |
| Storkiosken Lillesand AS | Wholesale & retail | 2006 |
| Stranda Eiendomsservice AS | Administrative & support | 2014 |
| Strandgata 11 AS | Real estate | 2014 |
| Strandgata 6 AS | Real estate | 2013 |
| Strandgaten 13 AS | Real estate | 1988 |
| Strandhaven Bistro Og Vinbar AS | Hospitality | 2022 |
| Strå by Cathrine AS | Other services | 2025 |
| Stykkene 1 AS | Real estate | 2016 |
| Styrhuset AS | Real estate | 2015 |
| Stålesen Invest AS | Real estate | 2018 |