3Com is a manufacturer best known for its computer network infrastructure products. The company was co-founded in 1979 by Robert Metcalfe, Bruce Borden, and Greg Shaw, and is headquartered in Marlborough, Massachusetts. The name 3Com comes from the company's focus on "Computers, Communication and Compatibility".

3Com is a leading global provider of enterprise and small-business networking solutions. The company offers a broad range of networking products including network switches, routers, wireless access points and controllers, IP voice systems, and intrusion prevention systems, among others. The company is based in Massachusetts, USA. From its 2007 acquisition of 100 percent ownership of H3C Technologies Co., Limited (H3C) -- what was initially a joint venture with China-based Huawei Technologies -- 3Com today has a leading market presence in China, and a significant networking market share in Europe, Asia, and the Americas. 3Com products are sold under the brands 3Com, H3C, and TippingPoint.

In 1997, 3Com merged with U.S. Robotics, a maker of dial-up modems, and owner of Palm, Inc.