Timothy Jackson Sullivan was born on April 15, 1944. He attended William & Mary in 1962 and graduated in 1966 with a Bachelors degree in government, a Phi Beta Kappa key, and membership in Omicron Delta Kappa. After receiving a law degree from Harvard University in 1969, Sullivan served in the Army Signal Corps during the Vietnam War. He received the Army Commendation Medal, First Oak Leaf Cluster and Bronze Star as a result of his services.

Sullivan returned to William & Mary in 1972 as an assistant professor at the Marshall-Wythe School of Law where he specialized in teaching contract law. He became an associate law professor in 1974, then full professor and associate dean in 1977. From 1981-1982, he was the visiting law professor at the University of Virginia School of Law. He served for nearly three years as the executive assistant of policy for then Governor Charles S. Robb. Sullivan returned to Marshall-Wythe in 1984, as the John Stewart Bryan Professor of Jurisprudence. He became dean of the law school in July 1985. He is a member of the Virginia and Ohio State Bar as well as a Fellow of the Virginia Bar Foundation and the American Bar Foundation. He also served as Chair of the Governing Board, Council of Presidents.

Sullivan was elected president of William & Mary on April 9, 1992 by the Board of Visitors and was sworn in as president on June 1, eight months before the college began its 300th anniversary celebration. Sullivan served as president until June 30, 2005.