- Tabletkoulu
- TactoTek
- Tag-Go
- Taiga Concept
- Taika3D
- Taitori
- Talas Electric
- Talea
- TalentAdore
- Tales by Trees
- Taloma
- Taloset
- Tamturbo
- Tanktwo
- Taom Tips
- Taputa
- Targetor
- Targovax
- Tarina Seikkailut
- TeacherGaming
- Teagle Group
- Team Action Zone (TAZ)
- Team Jolly Roger
- Teamspective
- Tehden
- Teicos Pharma
- Tekstarilla
- Tellabout
- Tellyo
- Tenboron
- Teraloop
- Terramonitor
- Tespack
- TestHouse Enko
- The Active Paper Company
- Theory Interactive
- The Warming Surfaces Company
- Theymes
- Thinglink
- ThinkDo
- ThirdPresence
- Tiitus
- TILT Biotherapeutics
- TimeGate Instruments
- Timespace
- Timma
- TinyApp
- Tippataulu
- Toadkings
- Tohtorille.fi
- Topaasia
- Topbox
- Toroidion
- Tosibox
- Toughbyte
- TPL Group
- Tracegrow
- Trackifi
- Trackinno
- Trainda
- Tramigo
- Transfluent
- Traplight
- Traxmeet
- Treamer
- Treebuddy
- Tree Men Games
- Treon
- Trestima
- Tribered
- Tribo
- Tridify
- Trivore
- TrueMed
- Truman Data
- Trussmatic
- Trustmary
- Tumplate
- Tuneko
- Tunnel Ground
- Tuotantoyhtiö Tuokio
- Tutor Tigers
- Tuxera
- Twice
- TWID
- Twisted Ark
- Two Men and a Dog
