| Triumph Studios | South Holland |
| Trivision | South Holland |
| TroBit B.V. | South Holland |
| Troopl | North Holland |
| Tropos Management B.V. | |
| Troublefree B.V. | South Holland |
| Trovita | |
| True | North Holland |
| True Bit | North Holland |
| Trueson B.V. | |
| Trunkrs | |
| Truston | Utrecht |
| TryFirst | Overijssel |
| Trymax Semiconductor Equipment B.V. | |
| TSD IT B.V. | Overijssel |
| TSM Business School | Overijssel |
| TSS Cross Media Group | South Holland |
| TTT Software | |
| TU Delft - Faculteit Elektrotechniek, Wiskunde en Informatica | South Holland |
| Tucana Telecom B.V. | North Brabant |
| Tune ICT | Gelderland |
| Tunga | |
| Tunix | Gelderland |
| Tur.ai B.V. | |
| Turff | |
| Tweede Golf | |
| Tweeweg IT | Gelderland |
| Twelve | Utrecht |
| Twentewebdesigners | |
| Twice | Limburg |
| Twincom Holding B.V. | North Brabant |
| Twinkle | Utrecht |
| Twins Software, Inc. | Gelderland |
| Twisted Bytes | |
| Two Tribes | Utrecht |
| TWP Computers B.V. | North Holland |
| TWS Benelux | |
| TXTWEB | Drenthe |
| Tykn B.V. | South Holland |
| Type Invaders | South Holland |
| Typeqast | North Holland |
| Typo3 Multishop | North Brabant |
| Typotheque | South Holland |
| Ub Technologies | |
| UbiOps | |
| Ubiqu Access B.V. | South Holland |
| UCTelecom | |
| UDefine | |
| UGA media | Utrecht |
| Uitelkaar.nl | |