| Leipää ja Sirkushuveja Oy Ab | Manufacturing | 2020 |
| Lightworks oy | Real estate | 2021 |
| Lindströms båt & bil Ab | Manufacturing | 2020 |
| Lindén Urakointi Oy | Construction | 2008 |
| Link Consulting Oy | Professional & scientific | 1984 |
| Loomi Oy | Professional & scientific | 2024 |
| LovEdu Oy | Professional & scientific | 2020 |
| Loval Oy | Manufacturing | 1986 |
| LoviSavi Ab | Arts & recreation | 2024 |
| Loviisa Kodit Oy - Lovisa Hem Ab | Real estate | 2020 |
| Loviisa Service Oy | Construction | 1998 |
| Loviisan Aarre Oy | Hospitality | 2002 |
| Loviisan Antiikki ja Kahvila Oy | Wholesale & retail | 2024 |
| Loviisan Asunnot Oy - Lovisa Bostäder Ab | Real estate | 1997 |
| Loviisan Asuntopalvelu Oy | Real estate | 2011 |
| Loviisan Automaalaamo Ky | Other services | 1984 |
| Loviisan Autovaraosa Oy | Wholesale & retail | 1997 |
| Loviisan Eläinklinikka Lovet Oy | Professional & scientific | 2015 |
| Loviisan Kelluva Kuningatar Oy | Real estate | 2023 |
| Loviisan Kiinteistöhuolto Oy-Lovisa Fastighetsservice Ab | Administrative & support | 2018 |
| Loviisan Kiinteistömaalaus Simpanen & Weckman Oy | Construction | 1990 |
| Loviisan Kirjakauppa Oy Lovisa Bokhandel Ab | Wholesale & retail | 2005 |
| Loviisan Leka Oy | Construction | 2007 |
| Loviisan Lukko Oy | Wholesale & retail | 2008 |
| Loviisan Lämpö Oy | Energy | 2020 |
| Loviisan Lämpöholding Oy | Financial services | 2020 |
| Loviisan MekHyd Oy Ab | Manufacturing | 2017 |
| Loviisan Palveluasunnot Oy - Lovisa Servicebostäder Ab | Real estate | 2025 |
| Loviisan Palvelukiinteistöt Oy Lovisa Servicefastigheter Ab | Real estate | 2025 |
| Loviisan Pelti ja Eristys Oy | Construction | 1993 |
| Loviisan Putki Oy | Construction | 2008 |
| Loviisan Puu Oy - Lovisa Trä Ab | Wholesale & retail | 1981 |
| Loviisan Puutarhakeskus Ky-Lovisa Trädgårdscenter Kb | Wholesale & retail | 1989 |
| Loviisan Syke Oy Ab | Arts & recreation | 2022 |
| Loviisan Sähköpiste Oy | Wholesale & retail | 1999 |
| Loviisan Tango Oy | Wholesale & retail | 1939 |
| Loviisan Vierasvenesatama OY | Hospitality | 2021 |
| Loviisan Vuokraus- ja Perintäpalvelu Oy | Real estate | 1996 |
| Loviisan Yrityspalvelu Oy - Lovisa Företagstjänst Ab | Professional & scientific | 1976 |
| Loviisan työauto oy | Wholesale & retail | 2025 |
| Lunch & Catering Fellman Oy | Hospitality | 2021 |
| Luomisen Liiteri Oy | Wholesale & retail | 2022 |
| M A Fellman Oy | Hospitality | 2007 |
| M Ristola Oy | Agriculture & fishing | 2018 |
| M. Forsten Oy Ab | Financial services | 2023 |
| MBOY-Masterbrokers Oy | Professional & scientific | 1992 |
| Moark OY | Professional & scientific | 2008 |
| Maamusta Oy | Arts & recreation | 2015 |
| Magire Oy | Wholesale & retail | 2026 |
| Mainostalo Dinero avoin yhtiö | Professional & scientific | 2017 |
| Majoituspalvelu Uninen Oy | Hospitality | 2019 |
| Malm Design Ab | Professional & scientific | 2008 |
| Marby Skogen Ab | Agriculture & fishing | 2026 |
| Marian pörinät Oy | Agriculture & fishing | 2021 |
| Markus Karlsson Oy Ab | Administrative & support | 2005 |
| Marlax Holding Oy | Financial services | 2019 |
| Matinkylän Kodit Oy | Real estate | 1988 |
| Mecema Oy | Construction | 2015 |
| Medair Oy | Wholesale & retail | 2015 |
| Merikone Oy | Real estate | 2025 |
| Meritta Bra Oy Ab | Wholesale & retail | 2004 |
| Mielikuvamatkaaja Oy | Education | 2017 |
| Militarius (LLC) Oy | Wholesale & retail | 2011 |
| Milkglass Games Oy | Information & communication | 2013 |
| Monature Ab Oy | Other services | 2016 |
| Monimieli Oy | Health & social care | 2026 |
| Mårten Henriksson Oy Ab | Professional & scientific | 1986 |
| New Me Oy | Professional & scientific | 2011 |
| Niko Kouvalainen Oy | Real estate | 2021 |
| Nirmata Oy | Construction | 2019 |
| NisseFix Automaalaamo Oy Ab | Other services | 2023 |
| Nord Sailing Oy | Administrative & support | 2026 |
| Nordic Packaging and Container (Finland) Holdings Oy | Real estate | 2016 |
| Norra Mind Oy Ab | Professional & scientific | 2015 |
| Norsko Oy | Real estate | 2016 |
| North Star marine Oy | Construction | 2024 |
| Nostokuljetus He-Wi Oy | Professional & scientific | 1983 |
| NovoChem Oy | Wholesale & retail | 2011 |
| Nykyterveys Oy | Administrative & support | 2023 |
| OY RGT-byrå AB | Agriculture & fishing | 2012 |
| Olympos Pizza Palvelut Oy | Hospitality | 2024 |
| Omega Building Oy/Ab | Construction | 1990 |
| Onokosa Oy | Professional & scientific | 2015 |
| Optirak Oy | Real estate | 2013 |
| Osuuskunta Icebreaker Productions | Information & communication | 2010 |
| Oy Ango Ab | Professional & scientific | 1987 |
| Oy Asianajotoimisto Nina Antas Advokatbyrå Ab | Professional & scientific | 2012 |
| Oy Asianajotoimisto Stefan Andersson Advokatbyrå Ab | Professional & scientific | 1990 |
| Oy Aug. Ljungqvist Ab | Transport & logistics | 1930 |
| Oy C & D Fastfood Ab | Hospitality | 1996 |
| Oy Country Caravan Ab | Wholesale & retail | 1987 |
| Oy Degerby Constructor Ab | Real estate | 1990 |
| Oy Diagonal Ab | Professional & scientific | 1990 |
| Oy Dispandersson Ab | Administrative & support | 1973 |
| Oy Duromek Ab | Manufacturing | 1988 |
| Oy F Tres Ab | Professional & scientific | 1996 |
| Oy Gymbalance Ab | Arts & recreation | 2018 |
| Oy Havsö Ab | Professional & scientific | 2015 |
| Oy J.Nybondas Ab | Real estate | 1990 |
| Oy JR-Service Ab | Wholesale & retail | 1994 |