| Mopedbil Formidling AS | Wholesale & retail | 2020 |
| Morris Invest AS | Real estate | 2012 |
| Mors Cafè AS | Hospitality | 2012 |
| Morsa Holding AS | | 2023 |
| Morten Engen Kranskole AS | Education | 2025 |
| Morten Kjærnes Consulting AS | Professional & scientific | 2005 |
| Morten Langbråten Eiendom AS | Real estate | 2015 |
| Morten Maskin AS | Construction | 2014 |
| Mortvold AS | | 2018 |
| Mortvold Invest AS | | 2025 |
| Mortvold Invest II AS | | 2025 |
| Moss Antikk Og Kunst AS | Wholesale & retail | 2025 |
| Moss Apartments AS | Real estate | 2019 |
| Moss Aromaterapi Og Massasje AS | Other services | 2026 |
| Moss Autocenter AS | Wholesale & retail | 2011 |
| Moss Automation AS | Manufacturing | 2004 |
| Moss Avis AS | Information & communication | 2014 |
| Moss Bad & VVS Senter AS | Construction | 2005 |
| Moss Bad Og Varme AS | Construction | 2022 |
| Moss Barbershop AS | Other services | 2026 |
| Moss Bil AS | Wholesale & retail | 2010 |
| Moss Bil-Båtpleie AS | Other services | 2026 |
| Moss Bilpleie Nemati AS | Other services | 2022 |
| Moss Bilsenter AS | Wholesale & retail | 2017 |
| Moss Bilservice AS | Other services | 2023 |
| Moss Bilskadesenter AS | Other services | 2010 |
| Moss Blikkenslagerverksted AS | Construction | 2019 |
| Moss Bryggeri AS | Manufacturing | 2018 |
| Moss Bygg AS | Construction | 1997 |
| Moss Båtservice AS | Manufacturing | 2015 |
| Moss Chalet AS | Real estate | 2026 |
| Moss Dekk AS | Other services | 2018 |
| Moss Dreierverksted AS | Manufacturing | 1972 |
| Moss Eiendom AS | Real estate | 2005 |
| Moss Eiendomsmegling AS | Real estate | 2023 |
| Moss Elektro AS | Construction | 1987 |
| Moss Folkebadstue AS | Other services | 2025 |
| Moss Fresh Food AS | Wholesale & retail | 2026 |
| Moss Frisørsenter Da | Other services | 2001 |
| Moss Frukt & Grønnsaker AS | Wholesale & retail | 2012 |
| Moss Glass Og Fasade AS | Construction | 2004 |
| Moss Grill AS | Hospitality | 2017 |
| Moss Grønnsaker AS | Wholesale & retail | 2024 |
| Moss Hagemaskinservice AS | Wholesale & retail | 2009 |
| Moss Helsesenter AS | Health & social care | 2024 |
| Moss Hospitality AS | Hospitality | 2010 |
| Moss Hotel AS | Real estate | 1969 |
| Moss Hus & Hage AS | Administrative & support | 2003 |
| Moss I Sentrum AS | Professional & scientific | 2016 |
| Moss Karosseri AS | Other services | 2022 |
| Moss Kiosk Og Spill AS | Wholesale & retail | 2023 |
| Moss Kirkegårdstjeneste Da | Administrative & support | 2005 |
| Moss Kiropraktikk Og Helse AS | Health & social care | 2017 |
| Moss Kjøkkenstudio AS | Wholesale & retail | 2025 |
| Moss Kjøleservice AS | Construction | 2022 |
| Moss Kobber & Blikk AS | Construction | 2012 |
| Moss Kunst Ramme AS | Wholesale & retail | 2010 |
| Moss Kurbadstue AS | Other services | 2021 |
| Moss Legesenter AS | Health & social care | 2025 |
| Moss Marina AS | Arts & recreation | 2000 |
| Moss Medisinske Senter AS | Health & social care | 2024 |
| Moss Minilager AS | Real estate | 2024 |
| Moss Naprapatklinikk AS | Health & social care | 2026 |
| Moss Næringspark Energisentral AS | Energy | 2022 |
| Moss Næringspark Øst 3 AS | Real estate | 2022 |
| Moss Næringspark ØST3 AS | Real estate | 2022 |
| Moss Ortopedisk Klinikk AS | Manufacturing | 2011 |
| Moss Padelsenter AS | Arts & recreation | 2025 |
| Moss Peis & Vedovn AS | Wholesale & retail | 2017 |
| Moss Pizzateria AS | Hospitality | 2022 |
| Moss Property Invest AS | Real estate | 2014 |
| Moss Pumpe- Og Ventilservice AS | Manufacturing | 2025 |
| Moss Regnskap & Bedriftsrådgivning AS | Professional & scientific | 2017 |
| Moss Restaurantdrift AS | Hospitality | 2014 |
| Moss Revisjonskontor AS | Professional & scientific | 2008 |
| Moss Rørlegger AS | Construction | 2024 |
| Moss Rørleggerservice AS | Construction | 1996 |
| Moss Shipping AS | Professional & scientific | 2006 |
| Moss Sjåfør Service AS | Transport & logistics | 2022 |
| Moss Snøryddingskompani AS | Administrative & support | 2019 |
| Moss Surplus Center Da | Wholesale & retail | 1992 |
| Moss Tavlemontering AS | Manufacturing | 2020 |
| Moss Taxi AS | Transport & logistics | 1994 |
| Moss Taxi Eiendom AS | Real estate | 1986 |
| Moss To-Takt AS | Other services | 2001 |
| Moss To-Takt Holding AS | Wholesale & retail | 2005 |
| Moss To-Takt Midtveien Eiendom AS | Real estate | 1967 |
| Moss Trafikkskole AS | Education | 2008 |
| Moss Transportforum Eiendom AS | Real estate | 1998 |
| Moss Trelast Eiendom AS | Real estate | 1967 |
| Moss Verfts Klubb SA | Real estate | 1988 |
| Moss VVS AS | Construction | 2015 |
| Moss Økonomiservice AS | Professional & scientific | 2011 |
| Mosse Krogen Sølving & Gustafsson Ans | Hospitality | 1993 |
| Mosseregionens Eiendoms Utvikling AS | Real estate | 2015 |
| Mosseregionens Næringsutvikling AS | Professional & scientific | 2006 |
| Mossesamlaget AS | | 2025 |
| Most Invest AS | | 2017 |
| Movar Næring AS | Water & waste | 2006 |
| MR Vedlikehold AS | Construction | 2022 |