Mary Jane McCallum is a citizen of the Barren Lands First Nation in Brochet, Manitoba. She attended the Guy Hill Residential School in The Pas for 11 years. She started her work as a dental assistant in 1973, attained her Dental Nursing Diploma in 1977, her Dental Therapy Diploma in 1979, and her Doctor of Dental Medicine in 1990. She worked as an Assistant Professor supervising 4th year dental students as well as providing dental treatment in Churchill in the first year after graduating. She moved on to provide dental care in all the northern nursing stations that have a clinical set-up as well as some of the southern health centres for the majority of the past 30 years. She worked as the Regional Dental Officer from 1996 – 2000 for the province of Manitoba.
She has spoken on many occasions to different groups throughout the country about the residential school experience. She was appointed to the Senate of Canada on Dec. 2, 2017, where she has continued to advocate for the rights of Indigenous Peoples. In addition to her work in the Senate Chamber, she has played an active role as a member of the Senate Standing Committee on Aboriginal Peoples and the Standing Committee on Energy, the Environment, and Natural Resources. She continues to work with Manitoba communities on issues including the advancement of oral and holistic health, child and family welfare, and environmental concerns.