Theresa Anne Tull (born October 2, 1936) was the United States Ambassador to Guyana (1987-1990) and Brunei from 1993 until 1996. Tull was born in Runnemede, New Jersey. She graduated from Camden Catholic High School, has a bachelor’s degree from the University of Maryland, and a master’s degree in Southeast Asian Studies from the University of Michigan in 1973.