| Hangon Vuokratalot Oy - Hangö Hyreshus Ab | Real estate | 1971 |
| Hangö Båtservice Kb - Hangon Venehuolto Ky | Manufacturing | 1989 |
| Hangö Fyrklöver Ab | Real estate | 2000 |
| Hangö Motorpunkt Ab | Other services | 2000 |
| Hanko Beach Club Oy Ab | Hospitality | 2020 |
| Hanko Grill House Oy | Hospitality | 2026 |
| Hanko Invest Oy | Real estate | 2021 |
| Hanko Trade Oy | Wholesale & retail | 2022 |
| Hanko Varastohotelli Oy | Transport & logistics | 2014 |
| Hanko-Nyt Oy | Information & communication | 2020 |
| Hankodent Ab | Health & social care | 2018 |
| Haukkaus Hanko Oy | Hospitality | 2022 |
| Hima&Huvila Oy | Real estate | 2014 |
| Hopearanta Holding Oy | Financial services | 2020 |
| ISL Consulting Ab | Real estate | 2016 |
| Ikas Fix Ab Oy | Construction | 2025 |
| Insinööritoimisto Rakentava Oy | Construction | 2023 |
| Investsam Ab | Professional & scientific | 2019 |
| Ithalco Oy | Arts & recreation | 2012 |
| J & J Hanko Trading Ab | Manufacturing | 2016 |
| JD Transport & Logistics Oy | Transport & logistics | 2019 |
| Juridisk byrå B-E Wickholm Kb Ky | Professional & scientific | 2002 |
| KH Cosmetics Oy | Other services | 2020 |
| KL-Vene Oy | Manufacturing | 2008 |
| Kraftverk Consulting OY | Professional & scientific | 2022 |
| KSS-Group Oy | Professional & scientific | 1989 |
| Kasvun Eväät Oy | Financial services | 2020 |
| Kb Hantrade Österlund & Co Ky | Professional & scientific | 1980 |
| Kb VN-Marine Ky | Wholesale & retail | 1989 |
| Kiinteistö Oy Hangon Nycanderinkatu 3 | Real estate | 2014 |
| Kiinteistö Oy Hangon Villa Aurora | Real estate | 2020 |
| Kiinteistö Oy Hangon kirjasto ja virastotalo - Fastighets AbHangö bibliotek och ämbetshus | Real estate | 1988 |
| Kiinteistö Oy Jonnika | Real estate | 1991 |
| Kiinteistö Oy Pellikanpojat | Real estate | 1998 |
| Kiinteistö Oy Pitkäkatu 43 Fastighets Ab | Real estate | 1964 |
| Kiinteistö Oy Tenala-Ikaros Fastighets Ab | Real estate | 1984 |
| Kiinteistö Oy Tvärminnen Häsälä | Real estate | 2003 |
| Kiinteistöosakeyhtiö Itä-Sataman Paviljonki | Real estate | 2010 |
| Kiinteistöyhtiö R Uusitalo Oy | Manufacturing | 1988 |
| Koifish Oy | Hospitality | 2020 |
| Kuhajärven Varastopalvelu Oy | Real estate | 2000 |
| Kurjenharju Oy | Real estate | 1989 |
| Kuumat Ravintolat Oy | Financial services | 2007 |
| Ky Hangon Auto- ja Venetalo - Bil- och Båthuset J.R. JanssonKb | Other services | 1981 |
| Lesman OY | Transport & logistics | 2026 |
| LU KiinteistöPalvelut Oy | Administrative & support | 2026 |
| LU Lukituspalvelu Oy - VN Låsservice Ab | Wholesale & retail | 1989 |
| LVI Huusko Oy | Construction | 2019 |
| La Chambre Oy | Wholesale & retail | 1998 |
| Ledsafe Oy | Professional & scientific | 2020 |
| Lehtovalli Oy | Other services | 2021 |
| Linnskär Invest Ab | Transport & logistics | 2020 |
| Lomahanko Oy | Information & communication | 2019 |
| Love out Loud Oy | Information & communication | 2021 |
| Love4C Ab | Other services | 2019 |
| M Steel & Craft Oy | Construction | 2026 |
| MBM-Halli Oy | Real estate | 2010 |
| Madame Pompadour Oy | Construction | 2025 |
| Majoitus ja Catering Hanko Oy | Hospitality | 2021 |
| Manika oy | Administrative & support | 2023 |
| Manner Kiinteistöt Oy | Real estate | 2022 |
| Mardos Oy | Hospitality | 2024 |
| Matheriks Oy | Financial services | 2021 |
| Matti Saarelainen Oy | Financial services | 1993 |
| Mattsson & Rajamäki Oy | Wholesale & retail | 2003 |
| MedDirect Oy | Wholesale & retail | 2002 |
| Medioptik Finland Oy | Wholesale & retail | 1964 |
| MeriCare Oy | Real estate | 1989 |
| Meriwellness oy | Arts & recreation | 2013 |
| Morfeemi Oy | Professional & scientific | 2008 |
| Mr Pepper Oy | Manufacturing | 1997 |
| Myrna Oy | Construction | 2026 |
| NEL Nordic Express & Logistics Finland Oy | Transport & logistics | 2022 |
| NVA-Service Ab Oy | Wholesale & retail | 2010 |
| Nomore Oy Ab | Real estate | 2009 |
| Nyysti Consulting Oy | Health & social care | 2014 |
| Nöjen Vin & Öl Oy | Hospitality | 2020 |
| Oi Hanko sushi restaurant Oy | Hospitality | 2024 |
| Osakeyhtiö Kairanmajat | Real estate | 1982 |
| Oskun Taksi Oy | Transport & logistics | 2019 |
| Oy Batom Ab | Financial services | 1990 |
| Oy Byssa Ab | Hospitality | 2024 |
| Oy CLE Invest Ab | Wholesale & retail | 1978 |
| Oy Caramel Catering Ab | Hospitality | 2013 |
| Oy Dinar Invest Ab | Financial services | 1985 |
| Oy Duplic Ab | Manufacturing | 1992 |
| Oy Ella Fishing Ab | Manufacturing | 1996 |
| Oy Forcit Ab | Manufacturing | 1897 |
| Oy HBY Docks Ab | Transport & logistics | 2009 |
| Oy HBY Invest Ab | Real estate | 2015 |
| Oy HBY Service Ab | Manufacturing | 2015 |
| Oy HSF Marine Ab | Arts & recreation | 2017 |
| Oy Hanfinans Ab | Real estate | 2003 |
| Oy Hango Ab | Wholesale & retail | 2000 |
| Oy Hangö Mekaniska Ab | Manufacturing | 1997 |
| Oy Hanko Boat Yard Ab | Real estate | 2014 |
| Oy Hanko Fortank Ab | Transport & logistics | 2025 |
| Oy Hanko Restpoint Ab | Hospitality | 1988 |
| Oy Hanko Terminals Ab | Transport & logistics | 1998 |
| Oy Havsgårdar Ab | Agriculture & fishing | 2008 |