The two that are most widely recognized are Vint Cerf and Bob Kahn, for TCP/IP, but that's just the start of it. There's JCR Licklider, who first imagined a global network of computers. There's Leonard Kleinrock, first ARPANET nod and packet-switching theory. Larry Roberts, who led development of ARPANET. Paul Baran independently invented packet switching. Donald Davies coined the term "packet" and also developed packet switching. Louis Pouzin also worked on TCP/IP. Jon Postel managed the IP standards and address assignments for decades. Ray Tomlinson invented email and the @ sign. Of course, we can't forget Tim Berneres-Lee, to whom we credit the invention of the web (HTTP, HTML, URLS, the first web browser and server).

So, eleven.

The Dream Machine is a history book by M. Mitchell Waldrop that tells the story of JCR Licklider.