Ungermann-Bass, also known as UB, was a computer networking company in the 1980s to 1990s. Located in Santa Clara, California, in the heart of Silicon Valley, UB was the first large networking company independent of any computer manufacturer.

UB was founded by Ralph Ungermann and Charlie Bass. Another leader in the company was John Davidson, vice president of engineering, who was one of the creators of NCP, the protocol suite of the ARPANET before TCP/IP.

UB specialized in large enterprise networks connecting computer systems and devices from multiple vendors, which was unusual in the 1980s. At that time most network equipment came from computer manufacturers and usually used only protocols compatible with that one manufacturer's computer systems, such as IBM's SNA or DEC's DECNet.

Many UB products initially used the XNS protocol suite and later transitioned to TCP/IP as it became an industry standard in the late 1980s.

UB was one of the first network manufacturers to sell equipment that implemented Ethernet on twisted pair wiring. UB's AccessOne product line initially used the pre-standard StarLAN and, when it became standard, 10BASE-T.

UB was bought by Tandem Computers in 1992. When Tandem was bought by Compaq in the late 1990s, UB was sold to NewBridge Networks. NewBridge was later acquired by Alcatel.