| Optolevel Oy | Manufacturing | 1994 |
| Oraviston Talli Oy | Agriculture & fishing | 2008 |
| Osaaja Group Oy | Administrative & support | 2026 |
| Osuuskassa Jäsenhuolto | Financial services | 1946 |
| Osuuskunta KuiHyvin | Other services | 2018 |
| Osuuskunta Linnavuori Kotikatsomot | Construction | 1998 |
| Othelo Holding Oy | Hospitality | 2021 |
| Other Art Oy | Other services | 2025 |
| Oti-Dent Oy | Real estate | 1981 |
| Ounas AI Oy | Information & communication | 2024 |
| Ovello Oy | Wholesale & retail | 2022 |
| Ovitas Isännöinti Oy | Real estate | 2020 |
| Oxio Oy | Construction | 2010 |
| Oxmet Ky | Manufacturing | 1980 |
| Oy Finnish Tough Wear Inc. | Wholesale & retail | 2015 |
| Oy Hifiauto.fi | Wholesale & retail | 2024 |
| Oy Joe Transfero Ltd | Professional & scientific | 1995 |
| Oy Scandic Levels Ab | Wholesale & retail | 1992 |
| Oy Solopro Ab | Arts & recreation | 1995 |
| Oy Trikoo-ompelimo Kehto | Manufacturing | 2020 |
| Ozan Oy | Real estate | 2021 |
| P. Kirstua Ky | Transport & logistics | 1990 |
| PF-Control Oy | Professional & scientific | 2009 |
| PIHA.na Oy | Administrative & support | 2021 |
| PML Yhtiöt | Construction | 2015 |
| PO & MS Oy | Financial services | 2024 |
| PP Audio Oy | Other services | 2026 |
| PR-Hedera Oy | Other services | 1998 |
| PSVTech Oy | Construction | 2017 |
| PT Kankainen Oy | Arts & recreation | 2023 |
| PVP-Kone Oy | Wholesale & retail | 1989 |
| PadelOnline Oy | Wholesale & retail | 2021 |
| PainavaPinta Oy | Construction | 2024 |
| Palaksi Oy | Wholesale & retail | 2014 |
| Palkkikova Oy | Construction | 2018 |
| Pantera Fuente Oy | Financial services | 2025 |
| Papu Design Oy | Professional & scientific | 2014 |
| Par-Met Team Oy | Manufacturing | 1997 |
| Pari passu Oy | Financial services | 2014 |
| Paroninhovi Oy | Construction | 2007 |
| PartMane Oy | Construction | 2025 |
| Parvi Invest Oy | Real estate | 2025 |
| Pauperes Oy | Health & social care | 2007 |
| Peliarkku Ky | Manufacturing | 2004 |
| Peltisepänliike Koskinen & Joensuu | Construction | 1979 |
| Peltisepänliike V. Vuorinen Oy | Manufacturing | 1981 |
| Peltityö Nousiainen Oy | Construction | 2023 |
| Pelton Oy | Construction | 2024 |
| Performance & skill coach Finland Oy | Education | 2019 |
| Perhekoti Pöllövaara Oy | Health & social care | 1995 |
| Perttu Lamminpohja Ky | Transport & logistics | 2005 |
| Perälän Saneeraus Oy | Construction | 2019 |
| Petrolipojat Oy | Manufacturing | 2022 |
| PharmaSic Oy | Wholesale & retail | 2022 |
| Pia ja Pasi Kahvila-Ravintola Maukas Avoin yhtiö | Hospitality | 2004 |
| Pieces to Pieces Oy | Wholesale & retail | 2023 |
| Piha Mäkinen Oy | Administrative & support | 2024 |
| Piha ja Rakennus Piitulainen Oy | Administrative & support | 2021 |
| Piha- ja maanrakennus Koski Oy | Construction | 2012 |
| Pihtikorven Vesiosuuskunta | Water & waste | 2003 |
| Piia Roos Oy | Education | 2015 |
| Piiritys Oy | Manufacturing | 2017 |
| PikkuPutiikit Handmade Tampere Osk | Wholesale & retail | 2021 |
| Pima-trans Oy | Transport & logistics | 1990 |
| Pinta-Team Ky | Construction | 1987 |
| Pintakäsittely Nokia Oy | Manufacturing | 1992 |
| Pintavilen Oy | Construction | 1992 |
| Pirkan Elektroniikka Oy | Manufacturing | 1979 |
| Pirkan Eläinlääkäri Oy | Professional & scientific | 2018 |
| Pirkan Metsurit Oy | Agriculture & fishing | 2026 |
| Pirkan Osuuspalvelu Cotilo | Construction | 1997 |
| Pirkan Piha- ja Remonttipalvelu Ky | Administrative & support | 2014 |
| Pirkan Rengas Jori Korhonen Ky | Wholesale & retail | 2000 |
| Pirkan Sähköhuolto Oy | Construction | 2011 |
| Pirkan Sähkövalvonta Oy | Professional & scientific | 2008 |
| Pirkan Säilyketukku Oy | Wholesale & retail | 2003 |
| Pirkan Talousneuvonta Oy | Professional & scientific | 1993 |
| Pirkan Teräpalvelu Ky | Manufacturing | 1985 |
| Pirkan Verkkopalvelu Oy | Construction | 1995 |
| Pirkanmaa Heat Ky | Wholesale & retail | 2005 |
| Pirkanmaan Aluesiivous Oy | Administrative & support | 2009 |
| Pirkanmaan Erityisratsastus Oy | Education | 2018 |
| Pirkanmaan Maatalouskauppa Oy | Wholesale & retail | 2008 |
| Pirkanmaan Macblue Oy | Real estate | 2001 |
| Pirkanmaan Menninkäinen Oy | Construction | 2003 |
| Pirkanmaan Painepesu Oy | Construction | 2013 |
| Pirkanmaan Pläkkärit Oy | Construction | 2020 |
| Pirkanmaan Purkutyö Oy | Construction | 2019 |
| Pirkanmaan TT Laatoitus Oy | Construction | 2023 |
| Pirkanmaan Teleurakointi Oy | Construction | 2020 |
| Pirkanmaan Vuokrakiinteistöt Oy | Real estate | 2018 |
| Pirkanmaan moniapu Oy | Construction | 2021 |
| Pirkanmaan sukellusetsintä Oy | Water & waste | 2020 |
| Pirkanmaan viher- ja ympäristöpalvelu Oy | Water & waste | 2020 |
| Pirkantti Oy | Hospitality | 2016 |
| Pirkka-Laskenta Oy | Administrative & support | 2024 |
| Pirkkalan Lasikaaren Helmi KOY | Real estate | 2017 |
| Pirteä porkkana Oy | Health & social care | 2024 |
| Piste Invest Oy | Financial services | 2021 |
| PlanScope Oy | Professional & scientific | 2022 |