| Snoro Holding AS | Financial services | 2005 |
| Socrates Eiendom AS | Real estate | 2014 |
| Sol Bilpleie Da | Other services | 2008 |
| Sol Bilpleie Elverum Da | Other services | 2011 |
| Sola Anker Butikkdrift AS | Wholesale & retail | 2021 |
| Solbakken Eiendom AS | Real estate | 2026 |
| Solbærvegen AS | Real estate | 2023 |
| Solbærvegen Eiendom AS | Real estate | 2015 |
| Sole Elverum AS | | 2001 |
| Sole Jømna AS | Real estate | 2026 |
| Sole Jømna AS | Real estate | 2023 |
| Solhaug Hansen Holding AS | Health & social care | 2019 |
| Sollia Hyttegrend Drift AS | Real estate | 2024 |
| Solstad Trysil AS | Real estate | 2023 |
| Solvesgate 4 AS | Real estate | 2008 |
| SP Kumar AS | Hospitality | 2025 |
| Spanish Porras AS | Hospitality | 2024 |
| Spol Tilbake AS | Professional & scientific | 2018 |
| Sporten 1952 AS | Wholesale & retail | 2026 |
| SSB Agri AS | Administrative & support | 2016 |
| St.Hanshaugen AS | Real estate | 2004 |
| Star Renhold AS | Administrative & support | 2025 |
| Stavåsbakken Holding AS | Financial services | 2017 |
| Stavåssvingen SA | Real estate | 2015 |
| Steen Arena AS | Real estate | 2005 |
| Steen Eiendom AS | Real estate | 1999 |
| Steen Eiendom Entreprenør AS | Construction | 2004 |
| Stengrundet Kiosk Da | Hospitality | 1995 |
| Stenrusten Eiendom AS | Wholesale & retail | 2018 |
| Stenrusten Invest AS | | 2025 |
| Stensby Trading AS | Wholesale & retail | 2005 |
| Stensløkkens Transporttjenester AS | Transport & logistics | 2018 |
| Stensve Invest AS | | 2025 |
| Stigin AS | Real estate | 2007 |
| Stil Blomster AS | Wholesale & retail | 2005 |
| Stillum AS | | 2024 |
| Stora Enso Skog AS | Wholesale & retail | 1985 |
| Stormyrveien Vestre SA | Real estate | 1970 |
| Stover.Gea AS | Information & communication | 2011 |
| Strandbygda Auto AS | Wholesale & retail | 2025 |
| Strandbygda Auto Invest Limited Nuf | | 2025 |
| Strandbygda Grunneierlag SA | Real estate | 1959 |
| Stratton Oakmont AS | | 2026 |
| Stri Pub AS | Hospitality | 2013 |
| Strøm & Norum Eiendom AS | Real estate | 2025 |
| Studio Belle AS | Other services | 2026 |
| Studio LW AS | Arts & recreation | 2023 |
| Studio Stine AS | Other services | 2024 |
| Stöver-Jonassen AS | Information & communication | 2005 |
| Sulland Elverum AS | Wholesale & retail | 1992 |
| SV Produksjon AS | Manufacturing | 2025 |
| Svartbekkvegen 84 AS | Wholesale & retail | 2006 |
| Svartholtveiene SA | Real estate | 1991 |
| Svensgaard Installasjon AS | Construction | 1991 |
| Svensgaard Invest AS | Real estate | 2005 |
| Swing IT Da | Wholesale & retail | 2000 |
| Synnøve Bergersen AS | Professional & scientific | 2005 |
| Syringengården AS | Real estate | 2004 |
| System-Tre AS | Wholesale & retail | 1994 |
| Syversrud Takst AS | Real estate | 2023 |
| Sætersmoen AS | Health & social care | 2025 |
| Søgård Skogsdrift AS | Agriculture & fishing | 2016 |
| Søir Husholdning AS | Water & waste | 2005 |
| Søir Næring AS | Water & waste | 2005 |
| Sømo AS | Transport & logistics | 2015 |
| Søndre Elverum Idrettshall AS | Arts & recreation | 2016 |
| T G Ruud Invest AS | | 1994 |
| T-H Gruppen AS | | 2022 |
| T.S.S. Holding AS | Wholesale & retail | 2020 |
| Takstion AS | Real estate | 2026 |
| Takstrådet Harald Juliussen AS | Real estate | 2012 |
| Tama Holding AS | | 2021 |
| Tannlege Annette Nordaas AS | Health & social care | 2012 |
| Taxi Elverum AS | Transport & logistics | 2019 |
| TB Telekom AS | Construction | 2021 |
| Temp Invest AS | Wholesale & retail | 2002 |
| Tennasfallet Holding AS | Real estate | 2021 |
| Terningen Arena Holding AS | Real estate | 2008 |
| Terningen Arena Idrett Og Kultur AS | Arts & recreation | 2008 |
| Terningen Arena Idrett Og Kultur Drift AS | Arts & recreation | 2008 |
| Terningen Event AS | Administrative & support | 2021 |
| Terningen Skog Da | Agriculture & fishing | 2006 |
| Texas Eiendom AS | Real estate | 2021 |
| Tigima AS | Real estate | 2015 |
| Tjenesten AS | Real estate | 2014 |
| Tmos Holding AS | Wholesale & retail | 2013 |
| Tmos Pharma AS | Wholesale & retail | 2018 |
| To Tre Snekkerverksted Ans | Manufacturing | 2001 |
| Toggens Budservice AS | Transport & logistics | 1999 |
| Tojan Invest AS | | 2020 |
| Tolverveien Ba | Real estate | 2002 |
| Tom Johansen Holding AS | Agriculture & fishing | 2020 |
| Tor Eiendom AS | Real estate | 2000 |
| Tor Harald Svendsen Holding AS | Real estate | 2016 |
| Tor Løkken AS | Wholesale & retail | 2021 |
| Tore Glad-Ørbak AS | Health & social care | 1994 |
| Tore Werner Olsen AS | Construction | 2013 |
| Torino Elverum AS | Hospitality | 1994 |
| Transherba AS | Professional & scientific | 1998 |
| Trebekk Service AS | Administrative & support | 2026 |