Sir Timothy John Berners-Lee OM KBE FRS FREng FRSA (born 8th June 1955) is a British computer scientist, who is credited with inventing the World Wide Web. On 25 December 1990 he implemented the first successful communication between an HTTP client and server via the Internet with the help of Robert Cailliau and a young student staff at CERN.

He was ranked Joint First in The Telegraph's list of 100 greatest living geniuses. Berners-Lee is the director of the World Wide Web Consortium (W3C), which oversees the Web's continued development, the founder of the World Wide Web Foundation and he is a senior researcher and holder of the 3Com Founders Chair at the MIT Computer Science and Artificial Intelligence Laboratory (CSAIL).

While an independent contractor at CERN from June to December 1980, Berners-Lee proposed a project based on the concept of hypertext, to facilitate sharing and updating information among researchers. While there, he built a prototype system named ENQUIRE. After leaving CERN, in 1980, he went to work at John Poole's Image Computer Systems Ltd in Bournemouth but returned to CERN in 1984 as a fellow. In 1989, CERN was the largest Internet node in Europe, and Berners-Lee saw an opportunity to join hypertext with the Internet: "I just had to take the hypertext idea and connect it to the Transmission Control Protocol and domain name system ideas and — ta-da! — the World Wide Web." He wrote his initial proposal in March 1989, and in 1990, with the help of Robert Cailliau, produced a revision which was accepted by his manager, Mike Sendall. He used similar ideas to those underlying the Enquire system to create the World Wide Web, for which he designed and built the first web browser and editor (called WorldWideWeb and developed on NeXTSTEP) and the first Web server called httpd (short for HyperText Transfer Protocol daemon).

The first Web site built was at CERN and was first put online on 6 August 1991. It provided an explanation about what the World Wide Web was, how one could own a browser and how to set up a Web server. It was also the world's first Web directory, since Berners-Lee maintained a list of other Web sites apart from his own.

In 1994, Berners-Lee founded the World Wide Web Consortium (W3C) at the Massachusetts Institute of Technology. It comprised various companies that were willing to create standards and recommendations to improve the quality of the Web. Berners-Lee made his idea available freely, with no patent and no royalties due. The World Wide Web Consortium decided that their standards must be based on royalty-free technology, so they can be easily adopted by anyone.