| # | Company name | Role | # of projects |
|---|---|---|---|
| 181 | Luis Vidal and Architects | Architect | 2 |
| 182 | M&G Investments | Investor | 2 |
| 183 | Mansilla + Tuñón Arquitectos | Architect | 1 |
| 184 | Mariano Bayón | Architect | 2 |
| 185 | Matos Castillo Arquitectos | Architect | 1 |
| 186 | MC2 Estudio Ingenieria | Structural engineering | 22 |
| 187 | Monereo, Meyer & Marinello Abogados | Law firm | 0 |
| 188 | Monthisa | Developer | 1 |
| 189 | Morph Studio | Architect | 1 |
| 190 | MTM Arquitectos | Architect | 0 |
| 191 | Multi Development Spain SA | Developer | 1 |
| 192 | Mutua Madrileña Automovilista | Owner | 1 |
| 193 | Naropa Properties S.L. | Owner | 1 |
| 194 | NB.35 Ingeniería | Structural engineering | 5 |
| 195 | NB35 S.L. Ingenieros | Structural engineering | 14 |
| 196 | Nexity España | Developer | 0 |
| 197 | NH Hoteles | Owner | 13 |
| 198 | NH Hotels | Tenant | 7 |
| 199 | Nieto Sobejano Arquitectos | Architect | 5 |
| 200 | No.Mad Arquitectura | Architect | 3 |