| MAKEEN Gas Equipment Denmark A/S | 8940 | Randers SV |
| Mariendal | 9000 | Aalborg |
| Marktlink Mergers & Acquisitions ApS | 2900 | Hellerup |
| Maskinfabrikken Automa ApS | 2500 | Valby |
| Maskinfabrikken Rational Aps | 2610 | Rødovre |
| Maskinsikkerhed ApS | 3500 | Værløse |
| Masytec A/S | 2605 | Brøndby |
| Max Weishaupt A/S | 2600 | Glostrup |
| Megatrade | 2650 | Hvidovre |
| MENY Kaffe | 9400 | Nørresundby |
| Micro Technic A-S | 5560 | Aarup |
| Midtjydsk Kran & Elektro a/s | 7400 | Herning |
| Mikkelsen Electronics A/S | 3520 | Farum |
| MillPart A/S | 6900 | Skjern |
| Mink-Bürsten ApS | 5492 | Vissenbjerg |
| Mirit Glas A/S | 2730 | Herlev |
| Momentum Energy Group A/S | 4000 | Roskilde |
| Mouritsen A/S | 7100 | Vejle |
| MTS Randers A/S | 8940 | Randers SV |
| Mul10 Metal A/S | 7130 | Juelsminde |
| Mul10 Prosafe A/S | 7130 | Juelsminde |
| Multi Køl & Energi A/S | 8220 | Brabrand |
| Munters A/S | 3520 | Farum |