| Local CrateIndustrials | Industrials | Chanhassen, United States | — | localcratemeals.com |
| LocalyticsConsumer | Consumer | Boston, United States | Raj Aggarwal | localytics.com |
| LocateAIOther | Other | San Francisco, United States | — | locate.ai |
| LogicGateOther | Other | Chicago, United States | Matt Kunkel | logicgate.com |
| LogixboardB2B | B2B | Seattle, United States | Julian Alvarez | logixboard.com |
| LorisB2B | B2B | Columbus, United States | Ethan Aaron | getloris.com |
| LosantOther | Other | Cincinnati, United States | Heath Doerr | losant.com |
| LOU Web TechnologiesEducation | Education | New York City, United States | — | louassist.com |
| LouisOther | Other | Labège, France | — | louis.design |
| Lounn MXFintech | Fintech | HIPODROMO-CUAUHTEMOC, Mexico | — | lounn.mx |
| lovepopOther | Other | Cambridge, United States | Wombi Rose | lovepopcards.com |
| LovysFintech | Fintech | Paris, France | João Cardoso | lovys.com |
| LuaConsumer | Consumer | New York City, United States | — | getlua.com |
| Lucky JuiceboxOther | Other | San Francisco, United States | — | luckyjuicebox.com |
| LullaaiOther | Other | Madrid, Spain | — | lullaai.com |
| LumeonHealthcare | Healthcare | Boston, United States | Robbie Hughes | lumeon.com |
| LuminaDataB2B | B2B | San Jose, United States | — | luminadata.ai |
| Lumos HelmetOther | Other | Boston, United States | Eu-wen Ding | lumoshelmet.co |
| LunarCrushB2B | B2B | Costa Mesa, United States | Joe Vezzani | lunarcrush.com |
| LunasondeIndustrials | Industrials | Cortaro, United States | — | lunasonde.com |
| Lux SemiconductorsOther | Other | Albany, United States | — | luxsemiconductors.com |
| LynqOther | Other | New York City, United States | — | lynqnetworks.com |
| Machinery PartnerOther | Other | Boston, United States | Benedikt Franke | machinerypartner.com |
| MadKuduB2B | B2B | Mountain View, United States | Francis Brero | madkudu.com |
| Mae - Making Auto EasyIndustrials | Industrials | Richmond, Canada | — | makingautoeasy.com |
| MainframeFintech | Fintech | San Francisco, United States | Mick Hagen | mainframe.co |
| MainstayB2B | B2B | Arlington, United States | Drew Magliozzi | admithub.com |
| Maiven EnergyB2B | B2B | Boulder, United States | — | askmaiven.com |
| make-tutoB2B | B2B | Tel Aviv, Israel | — | tutoit.io |
| MakeswiftOther | Other | Atlanta, United States | Robert Vogt | makeswift.com |
| ManateeOther | Other | Denver, United States | Tara Vaysman | getmanatee.com |
| Mani.MeOther | Other | Palo Alto, United States | Michelle Lam | manime.co |
| MANTLFintech | Fintech | New York City, United States | Nathaniel Harley | mantl.com |
| MapkinConsumer | Consumer | Cambridge, United States | — | mapkin.co |
| MapYourPropertyOther | Other | Toronto, Canada | — | mapyourproperty.com |
| Marble ARFintech | Fintech | Los Angeles, United States | — | marblever.se |
| Marine EdgeB2B | B2B | Haifa, Israel | — | marine-edge.com |
| Market IQFintech | Fintech | New York City, United States | — | themarketiq.com |
| Marlo TechnologiesFintech | Fintech | London, United Kingdom | — | marlo.online |
| Mast ReforestationOther | Other | Seattle, United States | David Milarch | mastreforest.com |
| MatchafulIndustrials | Industrials | Brooklyn, United States | Alissa Vitti | matchaful.com |
| MatcherinoOther | Other | La Jolla, United States | Justin Doster | matcherino.com |
| Material EvolutionIndustrials | Industrials | Belfast, United Kingdom | Liz Gilligan | materialevolution.co.uk |
| MathpixConsumer | Consumer | Santa Monica, United States | Nico Jimenez | mathpix.com |
| MavrckConsumer | Consumer | Boston, United States | Lyle Stevens | mavrck.co |
| Max RetailOther | Other | North Palm Beach, United States | — | maxretail.com |
| MaxRewardsFintech | Fintech | Atlanta, United States | Blake Squires | maxrewards.com |
| Maxwell FinancialFintech | Fintech | Denver, United States | Bryan Lovrien | himaxwell.com |
| MD AllyHealthcare | Healthcare | Philadelphia, United States | Jasmine Marcelin | mdally.com |
| MDaaS GlobalHealthcare | Healthcare | Boston, United States | Dot Ochieng | mdaas.io |