| AnycartConsumer | Consumer | Mountain View, United States | — | anycart.com |
| AnyscaleB2B | B2B | — | Robert Nishihara | anyscale.com |
| AnytypeB2B | B2B | — | Zhanna Dosmailova | anytype.io |
| AnytypeFintech | Fintech | Moscow, United States | Anton Starikov | anytype.io |
| ApiiroB2B | B2B | — | Idan Plotnik | apiiro.com |
| Aplic PlatformEducation | Education | North Vancouver, Canada | — | aplic.io |
| ApohaB2B | B2B | — | — | apoha.com |
| App SamuraiOther | Other | San Francisco, United States | Oguz Yildirim | appsamurai.com |
| ApperioB2B | B2B | — | Nicholas d'Adhemar | apperio.com |
| AppetasB2B | B2B | Redmond, United States | — | appetas.com |
| ApplicaB2B | B2B | Warsaw, Poland | Lukasz Borawski | applica.ai |
| Applied IntuitionB2B | B2B | — | Qasar Younis | appliedintuition.com |
| AppliedVRHealthcare | Healthcare | Los Angeles, United States | Matthew Stoudt | appliedvr.io |
| Approve.comFintech | Fintech | Dover, United States | Nat Mundel | approve.com |
| ApproximaB2B | B2B | San Francisco, United States | | approxima.ai |
| AppsemblerEducation | Education | Cambridge, United States | Nate Aune | appsembler.com |
| AppSheetOther | Other | Bellevue, United States | Praveen Seshadri | appsheet.com |
| ApptentiveConsumer | Consumer | Seattle, United States | Robi Ganguly | apptentive.com |
| AppwriteB2B | B2B | — | Eldad Fux | appwrite.io |
| AprilConsumer | Consumer | San Francisco, United States | | tryapril.com |
| Aptos OrbitalB2B | B2B | Mountain View, United States | — | aptosorbital.com |
| AQUAOSO TechnologiesIndustrials | Industrials | Folsom, United States | Tyler Kern | agcor.io |
| Aquifer MotionB2B | B2B | Austin, United States | — | aquifermotion.com |
| AraIndustrials | Industrials | New York City, United States | — | arascreens.com |
| ArbiaIndustrials | Industrials | Vancouver, Canada | — | arbia.io |
| ArborIndustrials | Industrials | — | Vipin Kalra | joinarbor.com |
| ARC Prize FoundationIndustrials | Industrials | — | | arcprize.org |
| Arc SimulationsIndustrials | Industrials | London, United Kingdom | — | arcsim.io |
| Arch FinanceFintech | Fintech | Brooklyn, United States | — | archfinance.com.au |
| ArcjetB2B | B2B | — | David Mytton | arcjet.com |
| ArclineB2B | B2B | — | | arcline-ai.com |
| ArctenB2B | B2B | San Francisco, United States | | arcten.com |
| ArenaConsumer | Consumer | San Francisco, United States | Guga Stocco | arena.im |
| ArextechFintech | Fintech | Toronto, Canada | — | arex.technology |
| Arga LabsB2B | B2B | San Francisco, United States | | argalabs.com |
| ArgilB2B | B2B | — | Thibaut Bitters | argil.ai |
| Ari CareOther | Other | Pärnu, Estonia | — | ari.shop |
| ArrivedFintech | Fintech | Seattle, United States | Ryan Frazier | arrived.com |
| ArrowHealthcare | Healthcare | United States | — | arrowhq.com |
| ArteraHealthcare | Healthcare | Santa Barbara, United States | Andrew Fenton | artera.io |
| ArticulateOther | Other | San Francisco, United States | | usearticulate.com |
| ArvistOther | Other | Wilmington, United States | — | arvist.ai |
| ArweaveOther | Other | London, United Kingdom | Sam Williams | arweave.org |
| ArzanaB2B | B2B | San Francisco, United States | | arzana.ai |
| ArzuleB2B | B2B | — | | arzule.com |
| AsanaB2B | B2B | — | Dustin Moskovitz | asana.com |
| AsanifyFintech | Fintech | Kolkata, India | Ruchit Garg | asanify.com |
| Asendia AIB2B | B2B | San Francisco, United States | Rihab Lajmi | asendia.ai |
| AsephaB2B | B2B | Toronto, Canada | — | asepha.ai |
| AshrB2B | B2B | — | | ashr.io |