| MasterTherm UK |
| Matamba Film Labs Trust |
| Matchstick Men Group Limited |
| Matrix Chambers Limited |
| Maxeon Solar Technologies, Ltd. |
| Maxingvest ag |
| Mazzoleni Galleria D'Arte SRL |
| MC Aviation Partners |
| MD Foods Limited |
| Meazure Learning |
| Media Reach Advertising Limited |
| Media Reach Group |
| Mediareach Star Limited |
| Meganexus Ltd |
| Megawra |
| Meiyume |
| Melitta Group |
| Mentor Hub Innovation, Mas Uliyati Cheklangan Jamiyati |
| Merck & Co., Inc |
| Mercurio Gestao Producoes e Acoes Colaborativas Ltda |
| Mercury Research SRL |
| Mercy Corps |
| MERMAID UK HOLDCO LIMITED |
| Met Foods Limited |
| Meta (formerly Facebook Inc) |