| Sorair TechnologiesOther | Other | Didcot, United Kingdom | — | sorair.co.uk |
| SoranoAIOther | Other | Stanford, United States | — | sorano.co |
| soundchartsConsumer | Consumer | Paris, France | Alexis Rousseau | soundcharts.com |
| Sourcery.AIB2B | B2B | London, United Kingdom | Boris Feld | sourcery.ai |
| Space RediOther | Other | Englewood, United States | — | spaceredi.com |
| SpacebackendOther | Other | Wilmington, United States | — | spacebackend.com |
| SparkChargeIndustrials | Industrials | Buffalo, United States | Joshua Aviv | sparkcharge.io |
| SpatialOther | Other | Cincinnati, United States | — | spatialabs.io |
| SpatialedgeB2B | B2B | Stellenbosch, South Africa | — | spatialedge.co.za |
| SpeclessConsumer | Consumer | Chicago, United States | — | gospecless.com |
| SpendCareFintech | Fintech | Franklin, United States | — | spend.care |
| SpheroOther | Other | Boulder, United States | Paul Berberian | sphero.com |
| SPIDR TechB2B | B2B | Torrance, United States | Rahul Sidhu | spidrtech.com |
| SPiNOther | Other | Frascati, Italy | — | spinintech.com |
| SpiralB2B | B2B | Seattle, United States | Farhan Ahmad | spiralup.co |
| Spitfire AthleteIndustrials | Industrials | San Francisco, United States | — | spitfireathlete.com |
| SplashB2B | B2B | Brisbane, Australia | Brett Goldstein | splashmusic.com |
| splashmobConsumer | Consumer | Santa Monica, United States | — | splashmob.app |
| SplittyOther | Other | Rishon LeZion, Israel | Itai Sadan | splittytravel.com |
| SPLTIndustrials | Industrials | Detroit, United States | Anya Babbitt | splt.io |
| SpocketB2B | B2B | Vancouver, Canada | Saba Mohebpour | spocket.co |
| Spoiler AlertIndustrials | Industrials | Boston, United States | Emily Malina | spoileralert.com |
| SporttradeConsumer | Consumer | Unionville, United States | Alex Kane | getsporttrade.com |
| Sprout Wellness SolutionsOther | Other | Toronto, Canada | Andrew Deutscher | sproutatwork.com |
| Sprout.aiOther | Other | London, United Kingdom | Roi Amir | sprout.ai |
| Spruce LabsB2B | B2B | Denver, United States | Andrew Levy | sprucelabs.ai |
| StabilitasConsumer | Consumer | Seattle, United States | Chase Cunningham | stabilitas.io |
| Stack MoxieB2B | B2B | Kirkland, United States | Talmage Egan | stackmoxie.com |
| StackBobB2B | B2B | Seattle, United States | — | stackbob.ai |
| StackeryB2B | B2B | Portland, United States | Chase Douglas | stackery.io |
| stagelinkOther | Other | Berlin, Germany | Christian Kemp | stagelink.com |
| Stance FitnessOther | Other | Harpenden, United Kingdom | — | stancehome.com |
| STAND+Other | Other | New York City, United States | — | weargales.com |
| StarStreetFintech | Fintech | Cambridge, United States | Jeremy Levine | starstreet.com |
| StatelessB2B | B2B | Boulder, United States | — | bestateless.com |
| StateraConsumer | Consumer | Brookline, United States | — | hellostatera.com |
| StatMuseOther | Other | San Francisco, United States | Eli Weiss | statmuse.com |
| StatPoint MedicalHealthcare | Healthcare | Curtis Bay, United States | — | statpointmedical.com |
| SteadOther | Other | Reigate, United Kingdom | — | joinstead.com |
| Stemma AIB2B | B2B | London, United Kingdom | Etai Lahav | stemma-ai.com |
| STHRIVEOther | Other | Dubai, United Arab Emirates | — | sthrive.com |
| StocklyOther | Other | Vitry-sur-Seine, France | Adrien Berthou | stockly.ai |
| StopLightB2B | B2B | Austin, United States | Marc MacLeod | stoplight.io |
| StoreCashFintech | Fintech | San Jose, United States | — | storecashapp.com |
| StoretaskerHealthcare | Healthcare | New York City, United States | — | storetasker.com |
| Storey The AppConsumer | Consumer | San Francisco, United States | — | storeytheapp.com |
| StormSensorIndustrials | Industrials | Seattle, United States | Erin Rothman | stormsensor.io |
| StoryTapOther | Other | Port Coquitlam, Canada | Margot Leong | storytap.com |
| StorywiseB2B | B2B | Ra'anana, Israel | Yoav Vilner | storywise.ai |
| str8batConsumer | Consumer | Bengaluru, India | Soham Sheth | str8bat.com |