- Tabletkoulu
- TactoTek
- Taiga Concept
- Taimer
- Taitori
- Talas Electric
- Talea
- TalentAdore
- Tales by Trees
- Taloset
- Tamturbo
- TangaReef
- Tanktwo
- Taom Tips
- Tapp Commerce
- Taputa
- Targovax
- Tarina Seikkailut
- Taurisol
- TAVIQ
- TeacherGaming
- Teagle Group
- Team Action Zone (TAZ)
- Team Jolly Roger
- TeamUp
- Teatiamo
- Tefismart
- Tellabout
- Tellybean
- Tellyo
- Teraloop
- Tespack
- The Active Paper Company
- Thinglink
- ThinkDo
- Tidy Technologies
- Tiitus
- TimeGate Instruments
- Timespace
- Timma
- TinyApp
- Tippataulu
- Tohtorille.fi
- Top Data Science
- Toroidion
- Tosibox
- TPL Group
- TrackDuck
- Trackinno
- TrademarkNow
- Trainesense
- Trä Kronor
- Traplight
- Traxmeet
- Treamer
- Treon
- Trestima
- TRIBL
- Tridify
- Trip Republic
- Trussmatic
- TTT-Applications
- Tuliotus
- Tuneko
- Tunnel Ground
- Tutor Tigers
- Tuup
- TWID
- TwoDads
- Two Men and a Dog
- Tziip