Ms. Mainville has a 4-year Bachelor of Arts degree specializing in Public Administration and Management Arts from the University of Lethbridge (Alberta). Upon graduating, she returned home to Couchiching to complete a contract in policy development for Chief and Council.    

After a few years working along the North Shore of Lake Huron as a researcher/writer, and economic development consultant, Sara returned home in 1997 to work in Lac La Croix and Couchiching First Nation. She was elected as a councilor and served as the economic development and youth portfolio-holder. Ms. Mainville was also the President of the Tribal Council.    

In 2004, Ms. Mainville completed her LL.B. at Queen's University in Kingston, Ontario. She was active with the Aboriginal Law Students' Association and other student affairs. Sara completed several environmental and criminal law classes, including the Correctional Law Project where she worked at Joyceville Federal Institution and represented inmates in disciplinary proceedings, parole hearings, and appeals of their convictions and sentencing.    

In 2005, Sara Mainville, joined the law firm of Nahwegahbow Corbiere as an Associate lawyer on several First Nation files. Ms. Mainville was responsible for a document management project involving an Aboriginal title claim in Ontario. In January 2007, Ms. Mainville completed her LL.M. thesis, titled: Manidoo Mazina'igan, An Anishinaabe perspective of Treaty 3.    

Ms. Mainville is also an Assistant Professor at Algoma University College where she teaches in the Law and Politics Department. Her research interests include the political philosophy of the Anishinaabe Nation, Anishinaabe law, and Constitutional and human rights.