- UART : Universal asynchronous receiver/transmitter
- uBER : uncorrectable Bit Error Rate. A metric for data corruption rate equal to the number of data errors per bit read after applying any specified error-correction method.
- UFS : (Universal Flash Storage) - intended successor to eMMC storage, see  and Samsung anouncement / Toshiba anouncement
- UMA : Uniform memory access, a computer memory architecture used in parallel computers
- UHD : Ultra high definition television, videoformats 4K UHD (2160p) and 8K UHD (4320p) - Youtube, Netflix, Vimeo & Videoland support streaming 4K (4096×3072 or 3840x2160)
- URB : (USB request block) - an URB is used to send or receive data to or from a specific USB endpoint on a specific USB device in an asynchronous manner.
- USB : (Universal Serial Bus) - a specification to establish communication between devices and a host controller (usually a personal computers). USB is intended to replace many varieties of serial and parallel ports.
- USB flash drive : a flash memory data storage device integrated with a USB (Universal Serial Bus) 1.1, 2.0, or 3.0 interface. USB flash drives are typically removable and rewritable, and much smaller in physical size than a floppy disc
- UUID : A universally unique identifier is an identifier standard used in software construction.