| Fastidium Centralis Ky | Real estate | 2019 |
| Fastidium Excelsior Ky | Real estate | 2026 |
| Fastidium Keilaranta Ky | Real estate | 2021 |
| Fastidium Neptunus Ky | Real estate | 2021 |
| Fastidium Tremulus Ky | Real estate | 2022 |
| Fastighets Ab Aallonranta | Real estate | 2021 |
| Fastighets Ab Amos | Real estate | 2020 |
| Fastighets Ab Arcadahallen | Real estate | 2016 |
| Fastighets Ab BMR:s Isabella | Real estate | 2019 |
| Fastighets Ab Babord | Real estate | 1965 |
| Fastighets Ab Drumsövägen 50 | Real estate | 2024 |
| Fastighets Ab Folkfast i Helsingfors | Real estate | 2008 |
| Fastighets Ab Hankens Isabella | Real estate | 2019 |
| Fastighets Ab Isabella Business | Real estate | 2024 |
| Fastighets Ab Jungfrusten | Real estate | 1992 |
| Fastighets Ab Korsmosståget 10 | Financial services | 2014 |
| Fastighets Ab Kyrkstallet Kiinteistö Oy | Real estate | 1970 |
| Fastighets Ab Lintock | Real estate | 1989 |
| Fastighets Ab Magistervägen 4 | Real estate | 1993 |
| Fastighets Ab Majsporten | Financial services | 1995 |
| Fastighets Ab Majstranden | Real estate | 2004 |
| Fastighets Ab Majstången | Real estate | 2024 |
| Fastighets Ab Nordstjärnan 1 | Real estate | 2020 |
| Fastighets Ab Nordstjärnan 2 | Real estate | 2020 |
| Fastighets Ab Pernå Solstrand Oy | Real estate | 1996 |
| Fastighets Ab Pluggvägen 10-12 | Real estate | 2016 |
| Fastighets Ab Pörtö Lillebo | Real estate | 1994 |
| Fastighets Ab Ria | Financial services | 1990 |
| Fastighets Ab Skarvörarna | Real estate | 1993 |
| Fastighets Ab Styrbord | Real estate | 1965 |
| Fastighets Ab Uddebo | Real estate | 2022 |
| Fastighets Ab Uustuhkaniemi | Real estate | 1995 |
| Fastighets Ab Victoria 3 | Real estate | 2014 |
| Fastighets Ab Victoria 4 | Real estate | 2014 |
| Fastighets Ab Villa Gunnarsberg | Real estate | 1993 |
| Fastighets Ab Vårholmen Kiinteistöt Oy | Real estate | 1995 |
| Fastighets Ab Yvonne | Real estate | 2024 |
| Fastighets Ab. Mästarvägen 9 i Borgå | Real estate | 1976 |
| Fastighetsaktiebolag Lyckebo | Real estate | 2026 |
| Fastighetsaktiebolag Mjölkanudden | Real estate | 2023 |
| Fastighetsaktiebolaget Balder | Real estate | 1913 |
| Fastighetsaktiebolaget Degerö Föreningshus | Real estate | 1945 |
| Fastighetsaktiebolaget Eriksgatan 2 | Real estate | 2018 |
| Fastighetsaktiebolaget Jungfruberg | Real estate | 1993 |
| Fastighetsaktiebolaget Kungsgatan 13 Kiinteistöosakeyhtiö Kuninkaankatu 13 | Real estate | 1938 |
| Fastighetsaktiebolaget Lillnäs Oy | Real estate | 1927 |
| Fastighetsaktiebolaget Neodomus | Real estate | 1906 |
| Fastighetsaktiebolaget Nyland | Real estate | 1900 |
| Fastighetsaktiebolaget Sirius | Real estate | 1898 |
| Fastighetsaktiebolaget Svensk Grund i Helsingfors | Professional & scientific | 1943 |
| Fastighetsaktiebolaget Sådö | Real estate | 2007 |
| Fastighetsaktiebolaget Villa Quisisana | Real estate | 1996 |
| Fastighetsbolag Jyväskylä Agora Ab | Real estate | 1998 |
| Fastmarkets Benchmark Administration Oy | Financial services | 2020 |
| Faston Oy Ltd | Real estate | 1960 |
| Fat Capital Oy | Financial services | 2018 |
| Fat Tony's Oy | Hospitality | 2025 |
| Fat X-Sports Oy | Wholesale & retail | 1995 |
| FatBird Oy Ltd. | Wholesale & retail | 2009 |
| FatCloth Oy | Wholesale & retail | 2012 |
| Father & Sons Oy | Professional & scientific | 2010 |
| Fathom Laboratory Oy | Professional & scientific | 2024 |
| Fatigué Oy | Manufacturing | 2018 |
| Fatty Globe Oy | Administrative & support | 2009 |
| FatumCom Oy | Wholesale & retail | 2023 |
| FatumTrans Oy | Transport & logistics | 2023 |
| Faunastic Oy | Information & communication | 2013 |
| Faunatar Finland OY | Wholesale & retail | 2018 |
| Fauni Licensing Corporation Oy | Administrative & support | 2020 |
| Faustina Oy | Arts & recreation | 2017 |
| Faux Oy | Wholesale & retail | 1973 |
| Faux Pas Advisory Oy | Professional & scientific | 2022 |
| Favore Oy | Professional & scientific | 2016 |
| Favorit verkkokauppa Oy | Wholesale & retail | 2014 |
| Favour The Brave Oy | Arts & recreation | 2024 |
| Fayeland Taxi Oy | Transport & logistics | 2024 |
| Fayrworks Oy | Information & communication | 2020 |
| Fazer Finland Oy | Manufacturing | 2017 |
| Fazer Konserttitoimisto Oy | Arts & recreation | 1946 |
| Fb-Group Oy | Construction | 2000 |
| Fbareekiyo Oy | Transport & logistics | 2022 |
| Fe Ohjelmointi Oy | Information & communication | 2023 |
| FeHill Oy | Real estate | 2019 |
| Feals Music Oy | Information & communication | 2023 |
| Fearless Founder Oy | Professional & scientific | 2024 |
| Fearless IT oy | Information & communication | 2022 |
| Fearless Nordic Oy | Information & communication | 2026 |
| Fearless Pinecone Oy | Information & communication | 2015 |
| Fearly Oy | Information & communication | 2020 |
| Fearnley Oy | Financial services | 2020 |
| Featly Oy | Information & communication | 2015 |
| Feature Media & Management Oy | Professional & scientific | 2025 |
| Fede Collective Oy | Other services | 2024 |
| Federalnoe Gosudarstvennoe Unitarnoe Predprijatie "Predprijatie po Upravleniju Sobstvennostju za Rubezom" Upravlenija Delami Prezidenta Rossijskoj Federatsii, Sivuliike Suomessa | Real estate | 2006 |
| Federico Fiorini Digital Services Oy | Information & communication | 2021 |
| FediDent Oy Ab | Health & social care | 2009 |
| Fedita Oy | Professional & scientific | 2025 |
| Feductor Oy | Professional & scientific | 2012 |
| Fedveba Oy | Hospitality | 2023 |
| FeedPackers Oy | Professional & scientific | 2016 |