| Baber S.C.P. | Barcelona |
| BackFund | Madrid |
| BackupInCloud | Madrid |
| Badiapp Technologies, S.L. | Barcelona |
| Balidea | |
| Balio Fintech, S.L. | Barcelona |
| Bamboo Energyy | Barcelona |
| Banner Agencia de Publicidad | Madrid |
| BAR Agency | |
| Barbara | |
| Barcelona Biomedical Research Park | |
| Barcelona Brain Health Initiative | Barcelona |
| Barcelona Cloud Technologies | Barcelona |
| Barcelona Code School | Barcelona |
| Barcelona Executive Business School | |
| Barcelona Graduate School of Mathematics | |
| Barcelona Health Hub | Barcelona |
| Barcelona Perl Mongers | Barcelona |
| Barcelona School of Economics | |
| Barcelona Supercomputing Center | Barcelona |
| Barcelona Supercomputing Center - Quantum Computing | Barcelona |
| Barcelona Technology School | Barcelona |
| Barcelona Ventures | Barcelona |
| Barcelona Ventures, S.L. | Barcelona |
| Barcelona Virtual | Barcelona |
| Bardo | Barcelona |
| Barlon Capital | |
| Barnaciber | Barcelona |
| Barnahosting | Barcelona |
| BarnaWeb | Barcelona |
| Basesoft | A Coruña |
| Basetis | |
| Basque Center for Applied Mathematics | Biscay |
| Basque Center on Cognition, Brain and Language | |
| BAU, Centro Universitario de Diseño de Barcelona | Barcelona |
| BCN Informática | Barcelona |
| BCN Peptides, S.A.U. | Barcelona |
| BCN3D Technologies, Inc. | |
| Bcnserveis.com | Barcelona |
| BCNWEBTEAM | Barcelona |
| Bcombinator | Barcelona |
| BCome | Barcelona |
| Bdeo | Madrid |
| BE Creativos | |
| Be Mobile Client, S.L. | Barcelona |
| Beabloo | Barcelona |
| Beato Digital | Alicante |
| BeBanjo | Madrid |
| BeCytes Biotechnologies | Barcelona |
| Bedrock Intelligence, S.L.U. | Asturias |