| BlockAviationFintech | Fintech | Dublin, Ireland | — | blockaviation.com |
| BloomfilterB2B | B2B | Cleveland, United States | — | thebloomfilter.com |
| Blooming HealthHealthcare | Healthcare | United States | Blooming Health | gobloominghealth.com |
| BloomsburyB2B | B2B | — | Alexandru Diaconu | bloomsbury.ai |
| BlueConsumer | Consumer | — | | heyblue.com |
| Blue FeverOther | Other | Marina del Rey, United States | Melissa Ambrosini | bluefever.com |
| Blue Navy RecoveryB2B | B2B | Irvine, United States | — | bluenavy.org |
| Blue StudiosFintech | Fintech | New York City, United States | — | bluestudios.io |
| Blueconomy AIB2B | B2B | Tinsukia, India | — | theblueconomy.ai |
| BluecoreOther | Other | New York City, United States | Fayez Mohamood | bluecore.com |
| bluefliteOther | Other | Austin, United States | — | blueflite.com |
| Blueprint RegistryFintech | Fintech | Seattle, United States | — | blueprintregistry.com |
| BlueshoeB2B | B2B | Boston, United States | Casey O'Grady | blueshoe.com |
| BlumaB2B | B2B | San Francisco, United States | | getbluma.com |
| BodyProHealthcare | Healthcare | Ra'anana, Israel | — | mybodypro.fit |
| BokioFintech | Fintech | Göteborg, Sweden | Viktor Stensson | bokio.se |
| Bold MetricsB2B | B2B | San Francisco, United States | Helder Antunes | boldmetrics.com |
| BoldrOther | Other | London, United Kingdom | — | shopboldr.com |
| Bolna AIB2B | B2B | Bengaluru, India | | bolna.ai |
| BondB2B | B2B | San Francisco, United States | | bondapp.io |
| BookendHealthcare | Healthcare | — | — | bookend.ai |
| BookoB2B | B2B | — | | bookoapp.com |
| Boom AIB2B | B2B | San Francisco, United States | | useboom.ai |
| BooqedConsumer | Consumer | Hong Kong, China | James Greaves | booqed.com |
| Boost RoboticsIndustrials | Industrials | Boston, United States | | boostrobotics.ai |
| BootLoopB2B | B2B | San Francisco, United States | | bootloop.ai |
| Boson MotorsIndustrials | Industrials | Milpitas, United States | Suman Mulumudi | bosonmotors.com |
| Botany.ioB2B | B2B | Seattle, United States | — | botany.io |
| BotikaConsumer | Consumer | — | — | botika.io |
| BoulderHealthcare | Healthcare | — | Alexander Marwood | boulder.care |
| BoundlessB2B | B2B | — | Xan Tanner | boundlesshq.com |
| BountifarmB2B | B2B | St Leonards, Australia | — | bountifarm.com |
| BoutiqB2B | B2B | Austin, United States | — | boutiq.co |
| BoxBotIndustrials | Industrials | United States | — | boxbot.io |
| BoxtreeOther | Other | Durham, United States | — | boxtree.gg |
| boxxtechOther | Other | Scottsdale, United States | — | boxxtech.ai |
| BPRXFintech | Fintech | Monterrey, Mexico | — | getbprx.com |
| BrainSpecHealthcare | Healthcare | Boston, United States | Praveen Kulkarni | brainspecmed.com |
| BraintrustB2B | B2B | — | Ankur Goyal | braintrustdata.com |
| Bramante BiologicsHealthcare | Healthcare | Cambridge, United States | | bramantebio.com |
| BranchFintech | Fintech | Minneapolis, United States | Atif Siddiqi | branchapp.com |
| Branching MindsOther | Other | New York City, United States | Ramon Miramontes | branchingminds.com |
| BranchtrackB2B | B2B | — | Ruslan Kolodochka | branchtrack.com |
| BrandfolderB2B | B2B | Denver, United States | Steve Trumbull | brandfolder.com |
| BraviB2B | B2B | San Francisco, United States | | bravi.app |
| BrelliumHealthcare | Healthcare | — | Justin Schweisberger | brellium.com |
| Bretton AIB2B | B2B | — | — | bretton.com |
| BrickantaB2B | B2B | Stockholm, Sweden | | brickanta.com |
| BrickwiseOther | Other | — | | brickwiseai.com |
| BridgeCare FinanceFintech | Fintech | Seattle, United States | — | getbridgecare.com |