Kay received a Bachelor of Business Administration degree from the University of Texas at Austin in 1962, and also a master's in International Affairs in 1964 and a Ph.D. in 1967 from Columbia University's School of International and Public Affairs.
David worked as an assistant professor of political science at the University of Wisconsin, Madison, from 1966 to 1970. He was an advisor in international organizational affairs to the United States mission to the United Nations from 1967 to 1968. Then he was an associate professor of political science at Barnard College of Columbia University, New York City in 1970-1971. At the University of Wisconsin, Madison, he began as associate professor of political science, then became professor of political science in 1971-1974. Kay was a director of an international research project of the American Society of International Law, Washington, DC in 1974. He was senior evaluator of programs at United Nations Educational, Cultural, and Scientific Organizations (UNESCO), Paris, France from 1974 to 1983. Since 1983 he was monitor of developing nuclear energy technologies at International Atomic Energy Agency, Vienna, Austria. Kay worked as the UN Chief Weapons Inspector from 1991 to 1992. Following that, he was Vice President of Science Applications International Corporation (SAIC) from 1993 to 2002. While at SAIC, he worked alongside Steven Hatfill until March 2002. Then, he was appointed as a Special Advisor for Strategy regarding Iraqi Weapons of Mass Destruction (WMD) Programs. He received the International Atomic Energy Agency's Distinguished Service Award and the U.S. Secretary of State's Commendation. After the 1991 Gulf War, Kay led teams of inspectors of the International Atomic Energy Agency in Iraq to search out and destroy banned chemical, biological, and nuclear weapons. Following the U.S. invasion of Iraq, he returned to the country, working with the Central Intelligence Agency and U.S. military in 2003 and 2004 to determine if Saddam Hussein's regime had continued developing banned weapons. On 23 January 2004 David Kay resigned his position as the head of the Iraq Survey Group.
He was a member of American Political Science Association.
David is married, his wife's name is Anita.