| Splinter Holding Oy | Helsinki | 2018 |
| SplitDecision Oy | Espoo | 2021 |
| Spole Oy | Tampere | 2023 |
| SponBrand Group Oy | Helsinki | 2026 |
| SponBrand Holding Oy | Helsinki | 2026 |
| SponVita Group Oy | Kuopio | 2026 |
| SponVita Holding Oy | Kuopio | 2026 |
| Sponcircle Oy | Virrat | 2021 |
| Sponcont Oy | Virrat | 2021 |
| Sponda International Oy | Helsinki | 2004 |
| Sponda Investment Properties A Oy | Helsinki | 2017 |
| Sponda Investment Properties B Oy | Helsinki | 2017 |
| Sponda Investment Properties C Oy | Helsinki | 2017 |
| Sponda Investment Properties D Oy | Helsinki | 2018 |
| Sponda Investment Properties E Oy | Helsinki | 2024 |
| Sponda Mezza Financing A Oy | Helsinki | 2017 |
| Sponda Mezza Financing B Oy | Helsinki | 2017 |
| Sponda Mezza Financing C Oy | Helsinki | 2017 |
| Sponda Mezza Financing D Oy | Helsinki | 2018 |
| Sponda Mezza Holding A Oy | Helsinki | 2017 |
| Sponda Mezza Holding B Oy | Helsinki | 2017 |
| Sponda Mezza Holding C Oy | Helsinki | 2017 |
| Sponda Mezza Holding D Oy | Helsinki | 2018 |
| Sponda PledgeCo A Oy | Helsinki | 2017 |
| Sponda PledgeCo B Oy | Helsinki | 2017 |
| Sponda PledgeCo C Oy | Helsinki | 2017 |
| Sponda PledgeCo D Oy | Helsinki | 2018 |
| Sponda PledgeCo E Oy | Helsinki | 2018 |
| Sponda Polar Development Mezzanine Holding Oy | Helsinki | 2022 |
| Sponda Resi BTR 1 Herttoniemi Oy | Helsinki | 2022 |
| Sponforest Holding Oy | Hytölä | 2025 |
| Sponforest Midco Oy | Hytölä | 2025 |
| Sponsor Capital Oy | Helsinki | 1989 |
| Sponsor Fund IV Ky | Helsinki | 2014 |
| Sponsor Fund V Ky | Helsinki | 2020 |
| Sponsor Fund VI Ky | Helsinki | 2024 |
| Sponsor GP V Oy | Helsinki | 2020 |
| Sponsor GP VI Oy | Helsinki | 2024 |
| Sponsor Partners Oy | Helsinki | 2014 |
| Spontan Capital oy | Helsinki | 1990 |
| Spontekno Oy | Kauniainen | 1990 |
| Sporax Oy | Espoo | 1980 |
| Sport Fund GP I Oy | Hämeenlinna | 2019 |
| Sport Fund I Ky | Hämeenlinna | 2019 |
| Sport Fund Management Oy | Hämeenlinna | 2019 |
| Sport Tester Markkinointi Oy | Kempele | 1988 |
| Sportcap Oy | Tampere | 2007 |
| Sports Investment Group Oy | Lahti | 2014 |
| Sportsmanship Oy | Helsinki | 2025 |
| Sportti Rahoitus Oy | Helsinki | 2013 |
| Sporttimania Oy | Lahti | 1966 |
| Springer Investment Management Oy | Espoo | 2021 |
| Springfield Capital Oy | Jyväskylä | 2019 |
| Springvest Oyj | Helsinki | 2012 |
| Sprint Capital Oy | Helsinki | 2020 |
| Spruce & Hill Holdings Oy | Helsinki | 2020 |
| Sprucepeak Invest Oy | Oulu | 2011 |
| Spurs Invest Oy | Vantaa | 2007 |
| Spyk Ltd, Oy, Ab | Helsinki | 1996 |
| Spyro Invest Oy | Nummenkylä | 2021 |
| Spöborg Capital Oy | Kirkkonummi | 2022 |
| Squidhold Oy | Jyväskylä | 2026 |
| Squirrel Nestments Oy | Hamari | 2020 |
| St. Karin Holding Oy | Helsinki | 2013 |
| St1 Finance Oy | Helsinki | 2016 |
| St1 Oy | Helsinki | 2006 |
| Stabile Finland Oy | Kempele | 2020 |
| Stable Haapakangas Oy | Kalajoki | 1992 |
| Stable Solutions Oy | Pirkkala | 2023 |
| Stabuli Oy | Espoo | 2014 |
| StadeBoss Holding Oy | Helsinki | 2022 |
| Stadi Holding Oy | Helsinki | 2019 |
| Stadshypotek AB (publ), filialverksamheten i Finland | Helsinki | 2011 |
| Stadsträdgården Holding Ab | Mariehamn | 2015 |
| StaffPoint 1 Oy | Helsinki | 2017 |
| StaffPoint Group Oy | Helsinki | 2025 |
| StaffPoint Holding Oy | Helsinki | 2025 |
| Staga Invest Oy | Oulu | 2022 |
| Stalemate Invest Oy | Sastamala | 1963 |
| Stall & Rink Capital Oy | Helsinki | 2026 |
| Stall Nysvidja Oy Ab | Lohja | 1998 |
| Stalwart Oy | Espoo | 2024 |
| Standard Capital Oy | Helsinki | 2001 |
| Stannum Oy | Äänekoski | 2018 |
| Stape Invest Oy | Helsinki | 2018 |
| Star hallintotoimet Oy | Turku | 1992 |
| Starap Oy | Toisvesi | 1993 |
| Staravia Oy | Tampere | 2020 |
| Starbucks Ab | Kauniainen | 1987 |
| Starckjohann Group Oy | Palokka | 2001 |
| Stardust Holding Oy | Turku | 2008 |
| Starfinance Oy | Oulu | 2016 |
| Stargate Group Oy | Helsinki | 2024 |
| Stargaze Oy | Helsinki | 2018 |
| Staria Oyj | Helsinki | 1987 |
| Starinita Oy | Lahti | 1998 |
| Stark Invest Oy | Helsinki | 2021 |
| Starlex Inc. Oy | Järvenpää | 1994 |
| Starlight Holding Oy | Aura Kk | 2026 |
| Starstore Oy | Halikko As | 2013 |