- Turbofan
- Turbojet
- Turbomolecular pump
- Turboprop
- Turbulence
- Turgor pressure
- Turning
- Turpentine
- Turquoise
- Tuyeres
- Twaron
- Twill
- Two-dimensional polymers
- Two-electron atom
- Two-phase flow
- Two-way radios
- Type 2 diabetes
- Type-ii superconductors
- Tyrosine
- UAV
- UHV
- USB
- USB-C
- Ulcerative colitis
- Ulcers
- Ulexite
- Ultimate tensile strength
- Ultramafic rock
- Ultrapure water
- Ultrasonic testing
- Ultrasonic welding
- Ultrasound
- Ultraviolet
- Umklapp scattering
- Underground hard-rock mining
- Underpinning
- Underwater acoustics
- Underwater environment
- Unicode
- Unit cell
- Unit of length
- Unit of measurement
- Unit operations
- Unit square
- Universal testing machine
- Universal time
- Universe
- Unreinforced masonry buildings
- Unsaturated fats
- Unsymmetrical dimethylhydrazine
- Upper critical solution temperature
- Uranium dioxide
- Uranium hexafluoride
- Uranium market
- Uranium ore
- Uranium trioxide
- Uranium-235
- Uranium-238
- Uranyl nitrate
- Urban heat islands
- Urban metabolism
- Urea
- Uric acid
- Urinary system
- User experience
- User interface
- Uterus
- Utility frequency
- V8 engine
- VA
- VEGF
- VLF
- VOC
- VPN
- VSEPR theory
- VSMOW
- VTOL
- VVER
- Vaccines
- Vacuum
- Vacuum bag moulding
- Vacuum flask
- Vacuum forming
- Vacuum furnace
- Vacuum permeability
- Vacuum pumps
- Vacuum tubes
- Vadose zone
- Vagus nerve
- Valence
- Valence electrons
- Valleys
- Valves
- Van der Waals force
- Vanadium oxide
- Vapor
- Vapor barrier
- Vapor intrusion
- Vapor lock
- Vapor pressure
- Vapor-liquid equilibrium
- Vaporization
- Vapour pressure of water
- Variable Specific Impulse Magnetoplasma Rocket
- Variable renewable energy
- Variable-range hopping
- Varistors
- Varves
- Vas deferens
- Vascular permeability
- Vasculogenesis
- Vaterite
- Vector fields
- Vector graphics
- Vegetable oil
- Vehicle
- Vehicle weight
- Vehicular automation
- Veins
- Venae cavae
- Ventilation
- Ventilator
- Venturi effect
- Venules
- Verdigris
- Vermiculite
- Vermilion
- Vertical and horizontal
- Vertically aligned carbon nanotube arrays
- Vesicles
- Vibrating-sample magnetometer
- Vibration
- Vibrator
- Vibrio cholerae
- Vickers hardness test
- Villas
- Vinegar
- Vinyl acetate
- Vinyl chloride
- Vinyl ester resin
- Vinyl group
- Vinyl polymer
- Viral
- Virial stress
- Virtual water
- Virtual work
- Viscoelasticity
- Viscometer
- Viscoplasticity
- Viscosity