| StreadyOther | Other | Trondheim, Norway | — | stready.com |
| StreamB2B | B2B | Boulder, United States | Thierry Schellenbach | getstream.io |
| StreamrootB2B | B2B | New York City, United States | Victorian Basta | streamroot.io |
| StreetMetricsConsumer | Consumer | Birmingham, United States | Maurice Riley | streetmetrics.com |
| StrobeB2B | B2B | Providence, United States | — | strobelabs.com |
| StrydOther | Other | Boulder, United States | Angus Nelson | stryd.com |
| StyleSageB2B | B2B | New York City, United States | Elizabeth Shobert | stylesage.co |
| SuccessionMatchingB2B | B2B | Moose Jaw, Canada | — | successionmatching.com |
| SuggesticOther | Other | Palo Alto, United States | Victor Chapela | suggestic.com |
| SumlyFintech | Fintech | New York City, United States | — | getsumly.com |
| SunairioOther | Other | Baltimore, United States | — | sunairio.com |
| Sunlight TechnologiesEducation | Education | San Francisco, United States | — | sunlight.is |
| SuntheticsB2B | B2B | New York City, United States | Daniela Blanco | sunthetics.io |
| Super DispatchFintech | Fintech | Kansas City, United States | Askar Bulegenov | mysuperdispatch.com |
| Superfan StudioB2B | B2B | Dallas, United States | — | superfan.studio |
| SuperpoweredOther | Other | Austin, United States | Dan Kantor | superpowered.com |
| SuperQuickQuestionOther | Other | Astoria, United States | — | superquickquestion.com |
| SurfLabOther | Other | Currumbin Waters, Australia | — | surflab.ai |
| Surge AfricaFintech | Fintech | Wilmington, United States | — | surgeafrica.co |
| Surgicure TechnologiesHealthcare | Healthcare | Charlestown, United States | — | surgicuretech.com |
| SurPlusMapOther | Other | Oslo, Norway | — | surplusmap.com |
| SURVIVROther | Other | Richardson, United States | — | survivr.com |
| SustainSoftConsumer | Consumer | Paris, France | — | sustainsoft.eu |
| Swag.comOther | Other | New York City, United States | Jeremy Parker | swag.com |
| SwiftComplyB2B | B2B | Dublin, Ireland | — | swiftcomply.io |
| SwingVisionOther | Other | Milpitas, United States | Swupnil Sahai | swing.tennis |
| Switchboard LiveOther | Other | Philadelphia, United States | Drew Stretch | switchboard.live |
| swivlB2B | B2B | Denver, United States | — | tryswivl.com |
| SwooveOther | Other | New York City, United States | — | swoove.delivery |
| SworkitIndustrials | Industrials | Bethesda, United States | Ryan Hanna | sworkit.com |
| SwymConsumer | Consumer | Seattle, United States | Praveen Krishnamurthy | getswym.com |
| SylloTipsB2B | B2B | Rome, Italy | — | syllotips.com |
| Symbl.aiB2B | B2B | San Jose, United States | Surbhi Rathore | rammer.ai |
| SympliFiFintech | Fintech | London, United Kingdom | — | symplifi.co.uk |
| SynackOther | Other | Redwood City, United States | Jay Kaplan | synack.com |
| SyncOnSet TechnologiesOther | Other | Los Angeles, United States | Vera Bobinaite | synconset.com |
| TablenderB2B | B2B | New York City, United States | — | tablender.com |
| tagSpaceOther | Other | Byron Bay, Australia | — | tagspace.com |
| TaizenB2B | B2B | Tallinn, Estonia | — | usetaizen.com |
| Take2.aiB2B | B2B | New York City, United States | — | take2.ai |
| TakeShapeB2B | B2B | Brooklyn, United States | Andrew Sprouse | takeshape.io |
| TalentQLB2B | B2B | Round Rock, United States | Opeyemi Awosika | talentql.com |
| Talimai SASEducation | Education | Orléans, France | — | brio.ink |
| TalivestB2B | B2B | Dublin, Ireland | Roly Walter | talivest.com |
| Talk-A-BotB2B | B2B | Budapest, Hungary | — | talkabot.net |
| TalkstackB2B | B2B | Singapore, Singapore | — | talkstack.ai |
| TangibleeB2B | B2B | Chicago, United States | Ori Marku | tangiblee.com |
| taptrip.coIndustrials | Industrials | London, United Kingdom | — | taptrip.co |
| Target ArmOther | Other | Ridgefield, United States | — | targetarm.com |
| TassoHealthcare | Healthcare | Seattle, United States | Ben Casavant | tassoinc.com |