| Ab Gröndahls Stuguthyrning - Gröndahlin Mökkivuokraus Oy | Hospitality | 1989 |
| Ab MarSan Oy | Construction | 2002 |
| Ab Matildas Fiske & Turist Oy | Transport & logistics | 1991 |
| Ab Nagu Service-Centrum | Real estate | 1987 |
| Ab Nagu fisk o bär - Nauvon kala ja marja Oy | Wholesale & retail | 2026 |
| Ab Ramsö Båtslip Oy | Manufacturing | 1987 |
| Ab Ruamera Oy | Real estate | 1993 |
| Ab Vahtera & Donner Oy | Manufacturing | 2022 |
| Airiston vesiosuuskunta | Water & waste | 2013 |
| Aktiebolaget Kaj Bredenberg Osakeyhtiö | Transport & logistics | 1996 |
| Anderoidi Oy Ab | Manufacturing | 2020 |
| Archipelago Holiday Ky | Hospitality | 2022 |
| Archipelago Suites Oy | Hospitality | 2020 |
| Arkkitehtitoimisto Aaro Söderlund Oy | Professional & scientific | 1990 |
| Arvgård Oy | Hospitality | 2026 |
| Baltic Ship Safe Oy | Education | 1989 |
| Bang & Olander Invest Ab | Real estate | 2021 |
| Berghamns Hav & Äng Ab | Administrative & support | 2021 |
| Bien Bonito Oy | Professional & scientific | 2025 |
| Billholm Ky | Hospitality | 1982 |
| Bock-Invest Oy | Professional & scientific | 1990 |
| Bystrand Catering Oy | Hospitality | 2007 |
| Cabet Oy | Wholesale & retail | 1998 |
| CarGott Kommanditbolag | Transport & logistics | 2010 |
| DataInnovations Oy | Information & communication | 1994 |
| Design Svanhild Åbonde Kb | Professional & scientific | 1984 |
| Destination Finland Seaside Kb | Administrative & support | 2010 |
| Direction N Oy | Wholesale & retail | 2018 |
| EW Kb metallhantverk | Manufacturing | 2011 |
| Emill Solutions Oy | Education | 2023 |
| Etcetera Networks Ab | Information & communication | 2019 |
| F. Holmberg Ab | Real estate | 1991 |
| Fastighets Ab Brinkhaga Kiinteistö Oy | Real estate | 1974 |
| Gräv & Transport Saarinen Oy Ab - Kaivuu & Kuljetus Saarinen Oy Ab | Transport & logistics | 1990 |
| Gullkronan Lohi Oy | Agriculture & fishing | 1987 |
| Haverön Lohi Oy | Agriculture & fishing | 1988 |
| Heikki Vento Oy | Arts & recreation | 2021 |
| Hemsundetin Ranta Osk | Real estate | 2018 |
| Hotel Stallbacken Nagu Oy Ab | Hospitality | 1997 |
| J & K Båtservice Öppet Bolag | Manufacturing | 2005 |
| JJ Julkisivut Oy | Construction | 2025 |
| JURMO SKÄRGÅRDSTJÄNST-SAARISTOPALVELUT Ab Oy | Manufacturing | 2007 |
| Jerrys Bygg och Planering Ab | Professional & scientific | 2025 |
| Kb Löfman Ky Gunilla Löfman | Professional & scientific | 1988 |
| Kiinteistö Oy Asessorinkatu 9 | Real estate | 2004 |
| Kirjailija Elämää Oy | Construction | 2025 |
| Kotila Bags Oy | Manufacturing | 1999 |
| Le Bon Ape Tit Oy | Hospitality | 2024 |
| Ltd Suomen Perussukellus Oy | Construction | 1995 |
| MIGS Marketing Oy | Professional & scientific | 2010 |
| Maekla Oy | Real estate | 2021 |
| Mekaform Ky | Manufacturing | 1985 |
| Mindoor Oy Ab | Construction | 1995 |
| Montano Oy | Professional & scientific | 2016 |
| Naficon Oy | Manufacturing | 1994 |
| Nagu Andelsbank | Financial services | 1924 |
| Nagu Miljonärsbryggan Ab | Real estate | 2018 |
| Nagu Restaurants Ab | Hospitality | 1987 |
| Nagu Seakayak Oy | Administrative & support | 2018 |
| Nagu Tak & Bygg Oy | Construction | 2026 |
| Odins båt & sjöentreprenad Ab Ltd | Transport & logistics | 2017 |
| Omagh Ab Oy | Hospitality | 2002 |
| Oppby Gård Ab | Health & social care | 2021 |
| Oy Cabino Ab | Real estate | 1992 |
| Oy Nagu Distillery Ab | Manufacturing | 1990 |
| Oy Nagu Harbour Ab | Transport & logistics | 2019 |
| Oy Parisiana de France Ab | Wholesale & retail | 1989 |
| Oy Port Wine Turku Ab | Hospitality | 1995 |
| Oy Vikom Marina Ab | Manufacturing | 1985 |
| Perfo Oy | Wholesale & retail | 1988 |
| Prissenterprise Ab | Hospitality | 2021 |
| Raiku Oy | Hospitality | 1991 |
| SD Investment Oy Ab | Real estate | 2020 |
| Saariston romu Oy | Wholesale & retail | 2022 |
| Saaristotien Palvelut Oy Ab | Wholesale & retail | 2021 |
| Saaristoverkot Holding Oy | Financial services | 2018 |
| Scorpio Oy Ab | Construction | 2023 |
| Skärgårdsnäten Ab | Information & communication | 2002 |
| Studio Douglas Sivén Ky | Professional & scientific | 1971 |
| Studio Fancy Oy | Other services | 2013 |
| Tackork Gård & Marina Oy | Hospitality | 2017 |
| Taide- ja Lahjapuoti Wallmo Oy | Wholesale & retail | 2008 |
| Transportservice Oy Sjövägen Ab | Transport & logistics | 1990 |
| Virtur Oy | Real estate | 2025 |
| Väståbolands Hyreshus Ab - Länsi-Turunmaan Vuokratalot Oy | Real estate | 2011 |
| Watertowine Oy | Professional & scientific | 2007 |