| AB Lovisa Bilskola Loviisan Autokoulu OY | Education | 2013 |
| AB Pling O Plong OY | Arts & recreation | 2009 |
| AC businessmix Oy Ab | Wholesale & retail | 2009 |
| AH Rakennus ja huolto Oy | Construction | 2022 |
| AS-Akatemia Oy | Education | 2025 |
| ATOR- Consultants Oy | Professional & scientific | 2013 |
| Ab Bokföringsbyrå Memo Kirjanpitotoimisto Oy | Professional & scientific | 1995 |
| Ab DeHi Oy | Professional & scientific | 2023 |
| Ab Dental-Rent Oy | Real estate | 1979 |
| Ab Däck-Rengas P. Lindfors Oy | Wholesale & retail | 1977 |
| Ab Fidentia Oy | Financial services | 1954 |
| Ab J&L HelpCare Oy | Administrative & support | 2014 |
| Ab J. Tidstrand Oy | Transport & logistics | 1956 |
| Ab Kaffe och konsultering Oy | Manufacturing | 2023 |
| Ab Lovisa Båtvarv | Manufacturing | 1974 |
| Ab Lovisa Färghandel - Loviisan Värikauppa Oy | Wholesale & retail | 1991 |
| Ab Lovisa Strandhotel - Loviisan Rantahotelli Oy | Hospitality | 2010 |
| Ab Saltbodan Oy | Hospitality | 1998 |
| Ab Sjöblom-Sport Oy | Wholesale & retail | 1932 |
| Ab Sääkär Korv - Varma Nakki Oy | Hospitality | 2016 |
| Ab Tikander Sea-Service Oy | Transport & logistics | 2002 |
| Ab WisdomHouse Oy | Other services | 2019 |
| Aktiebolaget Degerby Rusthåll | Real estate | 1930 |
| Alma Institutet Ab | Education | 2012 |
| Altamar Oy | Professional & scientific | 2001 |
| Amikes Oy | Financial services | 2003 |
| An-Stic avoin yhtiö | Construction | 2013 |
| Arkkitehtuuritoimisto Ilonen & Lautamo Kommandiittiyhtiö | Professional & scientific | 1988 |
| Arkkitehtuuritoimisto Kalevi Ilonen kommandiittiyhtiö | Professional & scientific | 1979 |
| Arppa Oy | Arts & recreation | 2023 |
| ArteSieni Oy | Agriculture & fishing | 2026 |
| Artengel Oy | Administrative & support | 2026 |
| Arton Rengaspalvelu Oy | Other services | 1990 |
| Auto-Inspect Finland Oy | Other services | 2005 |
| Auto-Rent Loviisa Ky | Administrative & support | 2020 |
| Autoni Digital Oy | Information & communication | 2016 |
| Avoin yhtiö Päivi Talvitie | Wholesale & retail | 2011 |
| Bansa Investment Finland Oy / Ab / Ltd | Manufacturing | 1982 |
| Batech Oy | Professional & scientific | 2023 |
| Be & Ba Oy | Health & social care | 2024 |
| Be Limitless Oy | Wholesale & retail | 2015 |
| Beekmann Company AB | Administrative & support | 2015 |
| Beibeifa food oy | Hospitality | 2024 |
| Bestrid Oy | Professional & scientific | 2012 |
| Bistro & Butik Kronan Oy | Hospitality | 2020 |
| Blueflame Solutions Ab | Professional & scientific | 2024 |
| Bluen Oy | Wholesale & retail | 2019 |
| CF Loviisa Oy | Arts & recreation | 2012 |
| CM-TECH Oy Ab | Other services | 2025 |
| CaFo Advisory Oy | Professional & scientific | 2024 |
| Cafe Riikka Oy | Hospitality | 1991 |
| Cafè Loviisa Oy | Hospitality | 2019 |
| Car Arts Ky | Other services | 1985 |
| Chene Invest Oy Ab | Financial services | 2019 |
| Clausal Computing Oy | Information & communication | 2010 |
| Conditoria Corint Ky | Hospitality | 1971 |
| Cowacode Oy | Information & communication | 2024 |
| Dajubhai OY | Hospitality | 2020 |
| DINA rahoituspalvelut Oy | Financial services | 2017 |
| E.D.E Harzi's Oy | Professional & scientific | 1989 |
| Ekman Metal Oy Ab | Manufacturing | 1981 |
| Eltete Oy | Manufacturing | 1987 |
| Eltete TPM Oy | Manufacturing | 1985 |
| Emporio K Oy | Wholesale & retail | 2025 |
| Epsilon Advanced Materials Oy | Professional & scientific | 2022 |
| Erviko Oy | Real estate | 1999 |
| Euroopan Runkoverkot Oy | Information & communication | 1999 |
| Exomedia Oy | Professional & scientific | 1985 |
| F-Tek Oy Ab | Manufacturing | 2013 |
| FS Infraurakointi Oy Ab | Construction | 2024 |
| Family Group Kiinteistöosakeyhtiö | Real estate | 2023 |
| Family Leipomo Oy | Manufacturing | 2022 |
| Fastighets Ab Brandensteinsgatan 19 - Kiinteistö Oy Brandensteininkatu 19 | Real estate | 1961 |
| Fastighets Ab Lovisa Drottninggatan 3 | Real estate | 2018 |
| Fastighets Ab Lovisa OF-Hus - Kiinteistö Oy Loviisan OF-Talo | Real estate | 1991 |
| Fastighets Ab Lovisa Stenborg Kiinteistö Oy | Real estate | 1975 |
| Fastighets-Ab Lovisa Sparåsen - Kiinteistö-Oy Loviisan Säästöharju | Real estate | 1964 |
| Fastighetsservice Bruce & Lång Ab | Administrative & support | 1996 |
| FeRva oy | Hospitality | 2017 |
| Finidea Oy | Professional & scientific | 1989 |
| Fishy Business Oy | Manufacturing | 2003 |
| Flitecons Oy | Transport & logistics | 2013 |
| FoxBunnyBox Oy | Wholesale & retail | 2020 |
| Furemu Oy | Construction | 2023 |
| GP Kuljetus Oy | Transport & logistics | 2012 |
| Grip Rose OY | Professional & scientific | 2016 |
| GalErna Oy | Hospitality | 2020 |
| Gamore Oy | Information & communication | 2022 |
| Gislom vattenandelslag | Water & waste | 1987 |
| Glasshouse Helsinki Oy | Professional & scientific | 2022 |
| Grottan Oy | Arts & recreation | 2016 |
| HB archipelago tours Oy Ab | Administrative & support | 2022 |
| HH Hinaus Oy/Ab | Transport & logistics | 1993 |
| HP-konsultointi ky | Professional & scientific | 1991 |
| Halfdrys Oy | Arts & recreation | 2010 |
| Hanssons såg Ab - Hanssonin saha Oy | Manufacturing | 1995 |
| Hautaustoimisto Begravningsbyrå Andersson & Co Oy Ab | Other services | 1994 |
| Havssmak Öb - Merenmaku Ay öppet bolag | Agriculture & fishing | 2010 |
| Heatly Oy | Energy | 2021 |
| Heatterm Oy | Manufacturing | 2023 |