Toniann received bachelors and masters degrees from Pennsylvania State University and then received a PhD from the University of Toronto in 1992. After that, Toniann spent 2 years as a postdoc at UCSD, and then 2 years as an assistant professor (in mathematics with a joint appointment in computer science) at the University of Pittsburgh. For the next four years, Toniann was a faculty member of the Computer Science Department at the University of Arizona. In the fall of 2001, Toniann moved back to Toronto, where she currently a professor in the Computer Science Department, with a joint appointment in Mathematics.