Cerf and his wife Sigrid both have hearing deficiencies; they met at a hearing aid agent's practice in the 1960s, which lead him to becoming an advocate for accessibility.
He left IBM to attend graduate school at UCLA where he earned his M.S. degree in 1970 and his PhD in 1972. Cerf studied under Professor Gerald Estrin and worked in Professor Leonard Kleinrock's data packet networking group that connected the first two nodes of the ARPANet, the first node  on the Internet, and "contributed to a host-to-host protocol" for the ARPANet.
While at UCLA, Cerf met Bob Kahn, who was working on the ARPANet system architecture. Cerf wrote the first TCP protocol with Yogen Dalal and Carl Sunshine, called Specification of Internet Transmission Control Program (RFC675), published in December 1974.
Cerf worked as assistant professor at Stanford University from 1972-1976 where he conducted research on packet network interconnection protocols and co-designed the DoD TCP/IP protocol suite with Kahn.
As vice president of MCI Digital Information Services from 1982 to 1986, Cerf led the engineering of MCI Mail, the first commercial email service to be connected to the Internet. In 1986, he joined Bob Kahn at the Corporation for National Research Initiatives as its vice president, working with Kahn on Digital Libraries, Knowledge Robots, and gigabit speed networks. It was during this time, in 1992, that he and Kahn, among others, founded the Internet Society (ISOC) to provide leadership in education, policy and standards related to the Internet. Cerf served as the first president of ISOC. Cerf rejoined MCI during 1994 and served as Senior Vice President of Technology Strategy. In this role, he helped to guide corporate strategy development from a technical perspective. Previously, he served as MCI's senior vice president of Architecture and Technology, leading a team of architects and engineers to design advanced networking frameworks, including Internet-based solutions for delivering a combination of data, information, voice and video services for business and consumer use.
During 1997, Cerf joined the Board of Trustees of Gallaudet University, a university for the education of the deaf and hard-of-hearing. Cerf himself is hard of hearing. He has also served on the university's Board of Associates.
Cerf, as leader of MCI's internet business, was criticized due to MCI's role in providing the IP addresses used by Send-Safe.com, a vendor of spamware that uses a botnet in order to send spam. MCI refused to terminate the spamware vendor. At the time, Spamhaus also listed MCI as the ISP with the most Spamhaus Block List listings.
Cerf has worked for Google as a Vice President and Chief Internet Evangelist since October 2005. In this function he has become well known for his predictions on how technology will affect future society, encompassing such areas as artificial intelligence, environmentalism, the advent of IPv6 and the transformation of the television industry and its delivery model.
Cerf helped fund and establish ICANN, the Internet Corporation for Assigned Names and Numbers. He joined the board in 1999, and served until November 2007. He was chairman from November 2000 to his departure from the Board.
Cerf was a member of Bulgarian President Georgi Parvanov's IT Advisory Council (from March 2002 – January 2012). He is also a member of the Advisory Board of Eurasia Group, the political risk consultancy.
Cerf is also working on the Interplanetary Internet, together with NASA's Jet Propulsion Laboratory and other NASA laboratories. It will be a new standard to communicate from planet to planet, using radio/laser communications that are tolerant of signal degradations including variable delay and disruption caused, for example, by celestial motion.
On February 7, 2006, Cerf testified before the U.S. Senate Committee on Commerce, Science, and Transportation's hearing on network neutrality. Speaking as Google's Chief Internet Evangelist, Cerf noted that nearly half of all consumers lacked meaningful choice in broadband providers and expressed concerns that without network neutrality government regulation, broadband providers would be able to use their dominance to limit options for consumers and charge companies like Google for their use of bandwidth.
Cerf currently serves on the board of advisors of Scientists and Engineers for America, an organization focused on promoting sound science in American government. He also serves on the advisory council of CRDF Global (Civilian Research and Development Foundation) and was on the International Multilateral Partnership Against Cyber Threats (IMPACT) International Advisory Board.
From 2011 to 2016, Cerf was chairman of the board of trustees of ARIN, the Regional Internet Registry (RIR) of IP addresses for United States, Canada, and part of the Caribbean. Until Fall 2015, Cerf chaired the board of directors of StopBadware, a non-profit anti-malware organization that started as a project at Harvard University's Berkman Center for Internet & Society. Cerf is on the board of advisors to The Liquid Information Company Ltd of the UK, which works to make the web more usefully interactive and which has produced the Mac OS X utility called 'Liquid'. Vint Cerf is a member of the CuriosityStream Advisory Board.
Since at least 2015, Cerf has been raising concerns about the wide-ranging risks of digital obsolescence, the potential of losing much historic information about our time – a digital "dark age" or "black hole" – given the ubiquitous digital storage of text, data, images, music and more. Among the concerns are the long-term storage of, and continued reliable access to, our vast stores of present-day digital data and the associated programs, operating systems, computers and peripherals required to access such.
In December 1997 he, along with his partner Robert E. Kahn, was presented with the National Medal of Technology by President Bill Clinton, "for creating and sustaining development of Internet Protocols and continuing to provide leadership in the emerging industry of internetworking."
Cerf was awarded the Award of Technology from the Telluride Tech Festival in 2002, also known as the Tesla Festival since the world's first AC hydro-power power plant was built in Telluride in 1891 by L.L. Nunn who purchased the generator and plans from George Westinghouse and Tesla.
^"Vinton G. Cerf, who developed together with Robert E. Kahn the TCP/IP protocol was awarded as a HPI Fellow on May 25th 2011. The HPI award is a tribute to his work for a new medium which influenced the everyday life of our society like no other one." "HPI Fellows & Guests". Archived from the original on May 20, 2011. Retrieved May 27, 2011.