| SB Subsea Services Ltd | Aberdeen Ab22 8 Nj Scotland | 2018 |
| SC Machining Ltd | Newcastle Upon Tyne Ne3 2Xj | 2022 |
| Scan Canada | St. John'S Nl A1B 3N7 | 2015 |
| Scan Tech AS | Stavanger | 1995 |
| Scana ASA | Paradis | 1976 |
| Scana Holding AS | Paradis | 2014 |
| Scandinavian Maritime Thailandsk AB | Th - Sarathani-Provinsen | 2014 |
| Scanmag AS | Ørnes | 2006 |
| Scanwell AS | Stavanger | 2007 |
| Schlumberger Danmark Aps Nuf | Oslo | 2010 |
| Schlumberger Norge AS | Stavanger | 1993 |
| Schlumberger Offshore Services Limited Nuf | Stavanger | 1996 |
| Schlumberger Overseas Nuf | Tananger | 2010 |
| Schmidt Winterdienst Und Kommunaltechnik GmbH | D-79830 St Blasien Schwartzwald | 1998 |
| Scms Holding AS | Florø | 2018 |
| Scomi Oiltools (Europe) Limited | Ab23 8Ef Aberdeen | 2000 |
| Score AS | Randaberg | 1993 |
| Score Europe Ltd | Randaberg | 2010 |
| Scott Wellservices Limited Nuf | Ky 15 7Ju Fife Scotland | 2019 |
| Sea Pearl WK Da | Ballangen | 2005 |
| SEA1 Marine Crew AS | Kristiansand S | 2024 |
| SEA1 Offshore AS | Kristiansand S | 2006 |
| SEA1 Offshore Crew AS | Kristiansand S | 2006 |
| SEA1 Offshore Invest AS | Kristiansand S | 2006 |
| SEA1 Offshore Maritime Personnel AS | Kristiansand S | 2009 |
| SEA1 Offshore Oscv AS | Kristiansand S | 2022 |
| SEA1 Offshore Rederi AS | Kristiansand S | 1854 |
| Seabed Vision AS | Klepp Stasjon | 2003 |
| Seadrill Norway Operations Ltd. Nuf | Stavanger | 2011 |
| Seadrill Offshore AS | Stavanger | 1972 |
| See Pukk & Grus AS | Straumen | 2020 |
| Seelian Limited | Dd10 8Ph Montrose Scotland | 2010 |
| Seistech Ltd | Aberdeen Ab11 6Yq Scotland | 2026 |
| Selnes Geoscience Consulting AS | Leknes | 2015 |
| Senior Consultants (UK) Limited | London Sw19 2Rr England | 1998 |
| Ser Entreprenør AS | Bergen | 2021 |
| Sevan Drilling Pte Ltd | Sg-Singapore 238868 | 2009 |
| SF Subsea Ltd | Aberdeen Ab21 0Ap Scotland | 2018 |
| Sf-Industri AS | Førde | 2012 |
| Sfax Petroleum Corporation AS | Oslo | 2018 |
| SG Deponi AS | Melhus | 2007 |
| Shaw Pipeline Services UK Limited | Great Yarmouth Nr31 0Nn | 2024 |
| Shelf Drilling (Norway) AS | Sandnes | 2023 |
| Shell Nigeria Exploration and Production Company Limited | Tananger | 2012 |
| Siai Holding AS | Tananger | 2017 |
| Sibelco Nordic AS | Åheim | 1992 |
| Sibelco UK Limited | Cheshire Cw11 4Tf England | 2019 |
| Siem Offshore Opco AS | Kristiansand S | 2024 |
| Sien AS | Randaberg | 2018 |
| Sigdalpukk AS | Nedre Eggedal | 2012 |
| Sigerfjord Sand AS | Sortland | 1993 |
| Sigersvold Invest AS | Kvinesdal | 2005 |
| Sigma Marine Services AS | Oslo | 2024 |
| Singel & Grus AS | Sola | 2026 |
| Singel & Grus Terminal AS | Sola | 2026 |
| Sinomine Specialty Fluids Limited Nuf | Ågotnes | 2004 |
| Sirio Sistemi Elettronici Spa | It- 59100 Prato | 2017 |
| Siv.Ing. Torgeir Aune AS | Trondheim | 2006 |
| SJC Engineering Design Ltd | Gb-Middlesbrough Ts8 9Ta | 2018 |
| Sjena D.O.O | Hr-10415 Novo Cice | 2013 |
| Sjøklar AS | Haugesund | 2016 |
| Sjølie Offshore AS | Oslo | 2018 |
| Skaland Graphite AS | Skaland | 2003 |
| Skattebøl Da | Rakkestad | 2020 |
| Skaugvoll Holding AS | Inndyr | 2012 |
| Skaugvoll Pukkverk AS | Inndyr | 2020 |
| Skibotn Grus Ans | Skibotn | 1991 |
| Skiferprodukter Design & Produksjon AS | Otta | 2013 |
| Skilbrei Petek AS | Tananger | 2021 |
| Skjold Singel & Stein AS | Skjold | 2011 |
| Skogberget AS | Storslett | 2014 |
| Skolt Pukkverk AS | Moss | 1992 |
| Skorgen Grus Og Transport AS | Vestnes | 1978 |
| Skorgen Søraas AS | Vestnes | 2021 |
| Skorovas Gruber AS | Trones | 2021 |
| Skøien Pukkverk AS | Odnes | 2014 |
| SLB Kristiansand AS | Kristiansand S | 2000 |
| Slippen Maskinentreprenør AS | Farsund | 2008 |
| Sm-Holding AS | Alta | 2008 |
| Sma Nordland AS | Mo I Rana | 2002 |
| Smeaheia Carbon Storage Ans | Stavanger | 2024 |
| Smit International Scotland LT | Cape Town 8000 | 1995 |
| Snarum Pukkverk AS | Vikersund | 2014 |
| Snåsa Naturstein AS | Steinkjer | 2013 |
| Snåsaskifer AS | Snåsa | 1989 |
| Sociedade De Montagens Metalomecanicas SA | Oslo | 2003 |
| Societe Miniere Dinguiraye | Oslo | 1999 |
| Sodexo Remote Sites Scotland Ltd | Aberdeen Ab 11 5Pj | 1995 |
| Soia II AS | Bergen | 2014 |
| Sokna Sand Og Pukk AS | Sokna | 2002 |
| Sollesnes Skiferbrudd AS | Jondal | 2011 |
| Solliåsen Pukkverk AS | Vegårshei | 2020 |
| Solstad Brasil AS | Skudeneshavn | 2000 |
| Solstad Brasil Holding AS | Skudeneshavn | 2020 |
| Solstad Construction AS | Skudeneshavn | 2007 |
| Solstad Mexico AS | Skudeneshavn | 2010 |
| Solstad Operations Holding AS | Skudeneshavn | 2020 |
| Solstad Shipholding AS | Skudeneshavn | 2020 |
| Solstad Superior AS | Skudeneshavn | 2016 |
| Solum Pukkverk AS | Holmestrand | 2012 |