- Tadiran
- Taiyo Yuden
- Talema Electronic, Inc.
- Taiwan Semiconductor Co., Inc.
- Taylor Microwave
- TDK Electronic Products Division
- TDK Semiconductor
- TDL, Inc.
- Tecate Group
- Teccor
- Tecdis
- Tecknit
- Tech Spray
- Teka Interconnection
- TelCom Semiconductor
- Teledyne Relays
- Tele Quarz Group
- Teltone Temic/Siliconix Terabit Technology, LLC
- Teradyne
- Tetsan
- TEW North America
- Texas Components Corp.
- Texas Instruments (TI)
- Thaler Corp.
- THAT Corp.
- Thermalloy
- Therm-O-Disc
- Thesys GmbH
- Thin Film Techology
- Thomas & Betts (T&B)
- Thomson-CSF
- Tocos America, Inc.
- Todd Products Corp.
- Tokin America
- Toko Toroid Corp. of Maryland
- Toshiba Total Power International
- Toyocom
- TRAK Microwave
- Transistor Devices, Inc.
- TranSwitch Corp.
- Trident Microsystems, Inc.
- TriQuint Triridge
- Tri-Tech, LLC
- TriTech Microelectronics
- Tru-Connector Corp.
- TRW
- Tseng Labs
- Tundra
- Tusonix
- TXC Corporation
