| Kestrel AIB2B | B2B | San Francisco, United States | | usekestrel.ai |
| Kestrel LabsOther | Other | Denver, United States | — | kestrellabs.com |
| Kestrl: Muslim Money AppFintech | Fintech | Waltham Abbey, United Kingdom | — | kestrl.io |
| Keyframe LabsB2B | B2B | — | | keyframelabs.com |
| KeysConsumer | Consumer | Missoula, United States | — | charmed.app |
| KeystoneBioHealthcare | Healthcare | Columbus, United States | — | keystonebio.co |
| Khaki AIOther | Other | Columbus, United States | — | khaki.email |
| KidasB2B | B2B | Philadelphia, United States | Daniel Donahoo | getkidas.com |
| KiddoWearOther | Other | San Francisco, United States | — | kiddowear.com |
| KilsarOther | Other | Virginia Beach, United States | — | kilsar.com |
| KimbaHealthcare | Healthcare | Tel Aviv, Israel | — | kimba.ai |
| Kimpton AIFintech | Fintech | San Francisco, United States | | kimpton.ai |
| KindredPMB2B | B2B | New York City, United States | — | kindredpm.ai |
| KineticOther | Other | New York City, United States | Haig Nalbandian | kineticcomp.com |
| KinometrixB2B | B2B | Fort Belvoir, United States | — | kinometrix.com |
| KinroB2B | B2B | San Francisco, United States | Parth Ainampudi | kinro.ai |
| KinsideFintech | Fintech | Pasadena, United States | Erin Luck | kinside.com |
| KitaFintech | Fintech | — | | usekita.com |
| kitchConsumer | Consumer | — | — | kitch.io |
| KitchenMateOther | Other | Toronto, Canada | Amir Farha | kitchenmate.com |
| Kitchn.ioB2B | B2B | Berlin, Germany | — | kitchn.io |
| KITROOther | Other | Renens, Switzerland | Eleanor Curry | kitro.ch |
| KlaimIndustrials | Industrials | Abu Dhabi, United Arab Emirates | Ali Jaffer | klaim.ai |
| KlashaFintech | Fintech | — | Jess Anuna | klasha.com |
| Klaus AIB2B | B2B | — | | klausai.com |
| Klavis AIB2B | B2B | — | | klavis.ai |
| Klira AIOther | Other | San Francisco, United States | — | getklira.com |
| KlumpFintech | Fintech | — | Adewale Oparinde | useklump.com |
| KnitConsumer | Consumer | Suffolk, United States | Eshaan Mitra | goknit.com |
| KnockB2B | B2B | United States | Chris Bell | knock.app |
| KnosticB2B | B2B | — | Gadi Evron | knostic.ai |
| KnowlifyB2B | B2B | San Francisco, United States | | knowlify.com |
| KoalaFintech | Fintech | Paris, France | — | hikoala.co |
| KoalaB2B | B2B | United States | — | home.koala.live |
| Koda HealthOther | Other | Houston, United States | Sonsoles Gonzalez | kodahealthcare.com |
| KodemB2B | B2B | — | Aviv Mussinger | kodemsecurity.com |
| Korall EngineeringOther | Other | Bergen, Norway | — | korall.io |
| KorsoB2B | B2B | San Francisco, United States | | korsoai.com |
| KoyalConsumer | Consumer | San Francisco, United States | | koyal.ai |
| KrakaB2B | B2B | — | — | gokraka.com |
| KredeteFintech | Fintech | New York City, United States | — | kredete.io |
| KriptosB2B | B2B | Tiburon, United States | — | kriptos.io |
| KubearkB2B | B2B | — | — | kubeark.com |
| KubecostB2B | B2B | United States | Webb Brown | kubecost.com |
| KumudaHealthcare | Healthcare | Boston, United States | — | kumuda.org |
| Kura TechnologiesFintech | Fintech | Boston, United States | — | kuratek.com |
| Kyten TechnologiesIndustrials | Industrials | — | | kytentech.com |
| La Fraise ProB2B | B2B | — | — | lafraise.pro |
| LabboxEducation | Education | Prishtina, Kosovo | — | labbox.education |
| LabbyOther | Other | Cambridge, United States | — | labbyinc.com |