| Parketti-Oy G. Lytz | Construction | 1934 |
| Parketti-R oy | Construction | 2022 |
| ParkettiStudio Helsinki Oy | Construction | 2022 |
| Parkettiliiga Oy | Construction | 2021 |
| Parkettiliike J Henriksson Oy | Construction | 1988 |
| Parkettiliike Lund Oy | Wholesale & retail | 2022 |
| Parkettiliike Widgren Oy | Construction | 2009 |
| Parkettistudio Turku Oy | Construction | 2025 |
| Parking Energy Oy | Energy | 2024 |
| Parkki Holding Oy | Professional & scientific | 2005 |
| ParkkiPate Oy | Transport & logistics | 2015 |
| Parkly Oy | Professional & scientific | 2021 |
| Parkourflow Oy | Arts & recreation | 2024 |
| Parkside Capital Oy | Financial services | 2022 |
| Parkstory Oy | Manufacturing | 2023 |
| Parkton Group Ab | Administrative & support | 2016 |
| Parlaro Oy | Manufacturing | 2025 |
| Parlay Technologies Oy | Information & communication | 2026 |
| Parmatic Oy | Construction | 1983 |
| Parmed Oy | Financial services | 1983 |
| Parmelina Oy | Professional & scientific | 1999 |
| Parmesan Oy | Professional & scientific | 1989 |
| Parnassia Oy | Financial services | 1992 |
| Paroc Group Oy | Professional & scientific | 2009 |
| Paroc Oy Ab | Manufacturing | 2014 |
| Parod Oy | Health & social care | 2013 |
| Parohoito Oy | Health & social care | 2006 |
| Parolan Peite Oy | Manufacturing | 1982 |
| Paroter Oy | Health & social care | 2004 |
| Parrestos Oy | Transport & logistics | 1984 |
| Parrot Consulting Oy | Financial services | 2021 |
| Parseli Oy | Financial services | 1978 |
| Parsifal Capital Oy | Financial services | 2025 |
| Parsing Capital Oy | Real estate | 2019 |
| Parsity avoin yhtiö | Professional & scientific | 2015 |
| Parsuma Oy | Information & communication | 2026 |
| Part of Salomaa Oy | Professional & scientific | 1987 |
| PartaMatti Oy | Arts & recreation | 2022 |
| Partaan Tilat Oy | Real estate | 2023 |
| Partanen Consulting Group Oy | Information & communication | 2018 |
| Partap Oy | Hospitality | 2025 |
| Parteam Oy | Construction | 1994 |
| Partek Oy Ab | Financial services | 1899 |
| Partenius Placeringar Ab | Financial services | 2022 |
| Parthenon Investments Oy | Financial services | 2025 |
| Partinen & Kotamäki Oy | Transport & logistics | 2016 |
| Partioaitta Oy | Wholesale & retail | 1942 |
| Partire Oy | Wholesale & retail | 1998 |
| Partner Hotelli Oy | Hospitality | 2006 |
| Partner List Oy | Professional & scientific | 1989 |
| Partner Nova Oy | Professional & scientific | 2022 |
| Partner in Prime Ab | Professional & scientific | 2025 |
| PartnerCo Granlund Oy | Financial services | 2025 |
| Partners at Noste Oy | Real estate | 2019 |
| Partnerus Oy Ltd | Wholesale & retail | 2006 |
| Parto Net Oy | Information & communication | 2025 |
| Partovi Design Oy | Professional & scientific | 2026 |
| Partscan Oy | Wholesale & retail | 2020 |
| Parttiputki Oy | Construction | 1973 |
| Parturi Kampaamo Bellino Oy | Other services | 1976 |
| Parturi-Kampaamo AM Hiuskulma Oy | Other services | 2002 |
| Parturi-Kampaamo Clou Oy | Other services | 2018 |
| Parturi-Kampaamo Hussain Oy | Other services | 2002 |
| Parturi-Kampaamo Loco Oy | Other services | 2011 |
| Parturi-Kampaamo Magnetic Oy | Other services | 2011 |
| Parturi-Kampaamo POP Oy | Other services | 1999 |
| Parturi-Kampaamo Poni Oy | Other services | 2011 |
| Parturi-Kampaamo Rollers Oy | Other services | 1987 |
| Parturi-Kampaamo Salon Capelli, avoin yhtiö | Other services | 1986 |
| Parturi-Kampaamo Sevilla Oy | Other services | 1981 |
| Parturi-Kampaamo Stil Oy | Other services | 2007 |
| Parturi-Kampaamo Stiletto Oy | Other services | 2017 |
| Parturi-kampaamo Lady & Gentleman Oy | Other services | 2022 |
| Parturi-kampaamo Töölön Tukkataikurit Avoin Yhtiö | Other services | 1994 |
| Parturikampaamo Martti & Rene Avoin Yhtiö | Other services | 2006 |
| Parturikampaamo Rita Juvonen Oy | Other services | 2004 |
| Parturikampaamo Sävy Oy | Other services | 2013 |
| Party Bugs Oy Ltd | Wholesale & retail | 2023 |
| Party Man Oy | Wholesale & retail | 2025 |
| Partypoopers Oy | Professional & scientific | 2024 |
| Parucor Oy | Health & social care | 2026 |
| Parvest Oy | Real estate | 1987 |
| Parvi & Co. Oy | Professional & scientific | 2026 |
| Parvi Collective Oy | Arts & recreation | 2022 |
| Parviainen & Co Oy | Professional & scientific | 2022 |
| Parviainen Consulting Oy | Professional & scientific | 2025 |
| Parvin Oy | Hospitality | 2025 |
| PasBoho Oy | Other services | 2020 |
| PasInvest Oy | Real estate | 1993 |
| Pasaati Holding Oy | Energy | 2021 |
| Pasandi Oy | Hospitality | 2018 |
| Pasanen Group Oy | Financial services | 2019 |
| Pasanen Holding Oy | Financial services | 2008 |
| Pasastar markkinointi Oy | Professional & scientific | 2020 |
| Pasemi Oy | Real estate | 1989 |
| Pasfalttin Oy | Construction | 2020 |
| Pashupati Foods Oy | Wholesale & retail | 2025 |
| Pasi Lehmusluoto Consulting ky - Water Systems Management Solutions Group | Professional & scientific | 1967 |
| Pasi Ruohonen Oy | Professional & scientific | 1997 |
| Pasi Salminen Photography Oy | Professional & scientific | 2016 |