| 1046 Soile Hiisiö Oy | Wholesale & retail | 2013 |
| AB Pihlacon OY | Construction | 1996 |
| Ar Sähkö OY | Construction | 2017 |
| Arkara OY | Hospitality | 2025 |
| Ab Andlins Plåt - Andlinin Pelti Oy | Construction | 2001 |
| Ab BMR Terapia Oy | Other services | 2014 |
| Ab Bygg-RA Oy | Real estate | 1993 |
| Ab Byggtjänst - Rakennuspalvelu Eddie Hanses Oy | Construction | 1995 |
| Ab Haijan | Financial services | 1988 |
| Ab Kristina Kök | Manufacturing | 1988 |
| Ab Kristinestads Bok- och Färghandel - Kristiinan Kirja- ja Värikauppa Oy | Wholesale & retail | 1998 |
| Ab Kristinestads näringslivscentral-Kristiinankaupungin elinkeinokeskus Oy | Professional & scientific | 2011 |
| Ab Krs Frakt & Spedition - Krs Rahti & Huolinta Oy | Transport & logistics | 2002 |
| Ab Krs Taxistation-Taksiasema Oy | Real estate | 1993 |
| Ab Möbel-Kaluste Mikael Oy | Wholesale & retail | 1998 |
| Ab Nibo Oy | Professional & scientific | 2018 |
| Ab Nya Hemgrund Oy | Administrative & support | 2015 |
| Ab Nyno Oy | Financial services | 1988 |
| Ab Service Ke-Sa Huolto Oy | Manufacturing | 1968 |
| Ab Sjöstadens Fastighetsutveckling - Merikaupungin Kiinteistökehitys Oy | Real estate | 2009 |
| Ab Svahl Plant Oy | Agriculture & fishing | 1996 |
| Ab Syd-Österbottens Trafikskolning-Suupohjan Liikennekoulutus Oy | Education | 2013 |
| AnHonestCreative Oy | Professional & scientific | 2023 |
| Andelslaget KrsNET | Information & communication | 2007 |
| Appsiu Oy | Information & communication | 2020 |
| Arvi Siili Oy | Transport & logistics | 1981 |
| Ateljee Raija avoin yhtiö | Manufacturing | 1991 |
| Aureum Noctua Oy Ab | Construction | 2020 |
| Avoin yhtiö ARock öppet bolag | Mining & quarrying | 2002 |
| Avoin yhtiö Advencor Öppet bolag | Professional & scientific | 2000 |
| Avoin yhtiö Mökkitalkkarit Andlin Stugvaktmästarna Öppet bolag | Administrative & support | 2014 |
| Bluevolt AB | Energy | 2022 |
| Bed-System Ky | Manufacturing | 2012 |
| Belle Bonbon Oy | Wholesale & retail | 2026 |
| Borealis spring Water OY | Wholesale & retail | 2023 |
| Botnia Bolt Oy Ab | Wholesale & retail | 1990 |
| Byggnadsbyrå CHN Ab | Construction | 2012 |
| Byggnadsbyrå E Hanses kommanditbolag Rakennustoimisto | Construction | 1966 |
| CC Property Oy Ab | Hospitality | 2020 |
| CPC Dagsmark Oy | Professional & scientific | 2013 |
| Café A Piece Of Cake Ab | Hospitality | 2022 |
| Cewal Grains Oy | Wholesale & retail | 2016 |
| Conmatic Ab Oy | Professional & scientific | 2003 |
| D Rundt Productions Ab | Professional & scientific | 2009 |
| DJ-Invest Oy | Transport & logistics | 2026 |
| Data Corner Öppet bolag | Other services | 2015 |
| Elektro-Palomäki Ky | Construction | 1981 |
| Elotec Finland Oy Ab | Administrative & support | 2003 |
| Entreprenör / Urakoitsija Westerlund öppet bolag | Construction | 2014 |
| Erämaavirta Oy | Manufacturing | 2006 |
| Fastighets Ab Kristinestads bostäder Kiinteistö Oy | Real estate | 1991 |
| Fastighets Ab Uttergården Kristinestad | Real estate | 1977 |
| Firma Henrik Höglund Ab | Agriculture & fishing | 2024 |
| Flinqen Ab Oy | Administrative & support | 2009 |
| Frankas Ab Oy | Real estate | 2018 |
| Frequency Event Management Ab | Arts & recreation | 2021 |
| GSR Advice Oy Ab | Administrative & support | 2011 |
| Greenmatex Oy | Manufacturing | 2021 |
| Greenrelax Oy | Administrative & support | 2021 |
| Hadzic Service Oy | Transport & logistics | 2025 |
| Helsingin Express Oy | Transport & logistics | 1987 |
| Hiushuone Frissa Ky | Other services | 2026 |
| Hopp Invest Oy | Real estate | 2016 |
| JLG-Service Öppet bolag | Construction | 2007 |
| JTT MONIAPU avoin yhtiö | Construction | 2016 |
| Junlin World Oy | Hospitality | 2017 |
| KEJA Palvelut Oy | Transport & logistics | 2021 |
| KFG Kristinestad OY | Real estate | 2000 |
| KJE Living Oy Ab | Real estate | 2025 |
| KMR Välitys AbOy | Real estate | 2025 |
| KRS Auto Center kb ky | Other services | 1987 |
| KRS Kiinteistökehitys Oy | Real estate | 2020 |
| KRS-Arena Oy | Arts & recreation | 2025 |
| Kala-Olli Oy | Agriculture & fishing | 2020 |
| Kasik Oy | Hospitality | 2018 |
| Kb HBS - Service | Real estate | 2016 |
| Kb Kristinestads Bokhandel-Kristiinan Kirjakauppa Ky Jani Sten | Wholesale & retail | 2002 |
| Kb Tempero Ky | Professional & scientific | 2009 |
| Kehä 1 Oy | Real estate | 2020 |
| Kiinteistö Oy JMMJ Ab | Real estate | 2009 |
| Kiinteistö Oy KRS Merituuli | Real estate | 2017 |
| Kiinteistö Oy Kalevan Navetta | Real estate | 2013 |
| Kiinteistö Oy Krepelin | Real estate | 1996 |
| Kiinteistö Oy Kristiinan Kulma | Real estate | 1953 |
| Kiinteistö Oy Kristiinankaupungin Kauppatori 1 | Real estate | 1999 |
| Kiinteistö Oy Talas | Real estate | 2025 |
| Kiinteistö Oy Teollisuuskatu 10 | Real estate | 1992 |
| Kone-Aittamäki Avoin yhtiö | Construction | 2010 |
| Kone-Ketonen Oy | Manufacturing | 1984 |
| Kontorstjänst Langels Kb | Administrative & support | 1986 |
| Koppö Carbon Oy | Manufacturing | 2024 |
| Koppö Energia Oy | Manufacturing | 2022 |
| Korken Capital Oy Ab | Real estate | 2024 |
| Koulutuspalvelu Brickan Oy | Education | 2022 |
| KrisSport Ky | Arts & recreation | 2003 |
| Kristiina sub Oy | Hospitality | 2024 |
| Kristiina-Beds Ky | Manufacturing | 2006 |
| Kristiinan Auto-Bonus Oy | Wholesale & retail | 1991 |
| Kristiinan Romu Oy | Wholesale & retail | 2003 |
| Kristinestad Vin & Sprit oy | Hospitality | 2021 |