Chris Axworthy, founding dean of the TRU Law School, resigned on Monday.
Citing a personnel issue related to Axworthy's departure, university administration would not comment on his resignation.
Anne Pappas has been appointed interim dean of law as TRU seeks a permanent replacement.
With three decades of experience as a law professor and a former dean of the University of Manitoba law school, Axworthy was considered a strong asset for the new school when he was hired in 2010.
Axworthy also served three terms as an NDP MP representing Saskatoon-Fairview in the 1980s and '90s. He ran unsuccessfully for the federal Liberals in 2004. He also serves as president of the Institute of Parliamentary and Political Law.
Upon arriving on campus, Axworthy described his TRU role as a once-in-a-lifetime opportunity.
"There hasn't been a new law school (in Canada) for 35 years," he said. "These opportunities don't come along often. When they do, you catch on and go with them."
Pappas had served as founding assistant dean at TRU since joining the law school faculty in 2010.
The law school opened in 2011. It's preparing to receive its third cohort of students and will graduate its first class next year.
Axworthy's departure is the third prominent faculty resignation in recent months. Michael Mehta, dean of arts, and Barbara Paterson, dean of nursing, resigned their positions in March. No explanation was given for those departures, either.