American computer scientist who is considered one of the founders of the Internet.

In 1965 Cerf received his bachelor's degree in mathematics from Stanford University, California, U.S. He then worked for IBM (International Business Machines Corporation) as a systems engineer before attending the University of California at Los Angeles (UCLA), where he earned a master's degree in computer science in 1970. He returned to Stanford and completed his doctorate in computer science in 1972.

While at UCLA, Cerf wrote the communication protocol for the ARPANET (Advanced Research Project Network; see DARPA (Defense Advanced Research Projects Agency)), the first computer network based on packet switching, a heretofore untested technology. (In contrast to ordinary telephone communications, in which a specific circuit must be dedicated to the transmission, packet switching splits a message into “packets” that travel independently over many different circuits.) UCLA was among the four original ARPANET nodes. While working on the protocol, Cerf met Robert Kahn (Kahn, Robert Elliot), an electrical engineer who was then a senior scientist at Bolt Beranek & Newman. Cerf's professional relationship with Kahn was among the most important of his career.

In 1972 Kahn moved to DARPA as a program manager in the Information Techniques Program Office (IPTO), where he began to envision a network of packet-switching networks—essentially, what would become the Internet. In 1973 Kahn approached Cerf, then a professor at Stanford, to assist him in designing this new network. Cerf and Kahn soon worked out a preliminary version of what they called the ARPA Internet, the details of which they published as a joint paper in 1974. Cerf joined Kahn at IPTO in 1976 to manage the office's networking projects. Together they produced TCP/IP (Transmission Control Protocol/Internet Protocol), an electronic transmission protocol that separated packet error checking (TCP) from issues related to domains and destinations (IP).

Cerf's work on making the Internet a publicly accessible medium continued after he left DARPA in 1982 to become a vice president at MCI Communications Corporation (after 1998, WorldCom, Inc.). While at MCI he led the effort to develop and deploy MCI Mail, the first commercial e-mail service to use the Internet. In 1986 Cerf became a vice president at the Corporation for National Research Initiatives, a not-for-profit corporation located in Reston, Virginia, that Kahn, as president, had formed to develop network-based information technologies for the public good. Cerf also served as founding president of the Internet Society from 1992 to 1995. In 1994 Cerf returned to WorldCom as a senior vice president, and in 1998 he became the first chairman of the Internet Corporation for Assigned Names and Numbers, the group that oversees the Internet's growth and expansion.

In addition to his work on the Internet, Cerf served on many government panels related to cyber-security and the national information infrastructure. A fan of science fiction, he was a technical consultant to one of author Gene Roddenbury's posthumous television projects, Earth: Final Conflict. Among his many honours was the National Academy of Engineering's Charles Stark Draper Prize (2001).