Martha Fraser was Robert Fraser's mother and Benton Fraser's grandmother. A resident of the Canadian territories, she worked as a travelling librarian with her husband George and travelled across the North, moving from one Inuit community to the next. When Caroline Fraser was murdered in 1968, Benton Fraser was sent to live with his grandparents. Martha Fraser raised her grandson to be chivalrous and refused to indulge him so he would be tough, responsible and courageous.
In the episode One Good Man, Benton Fraser tells of a day he went swimming and saw his grandmother in a bathing suit for the first time; her arms were covered in burn scars and he discovered she had once worked as a primary school teacher and had rescued her pupils from a fire by leading them into a river.
Martha Fraser was portrayed by the late Canadian actress Frances Hyland.
Martha Fraser is only seen once as a ghost in her grandson's hospital room while he is recovering from a gunshot wound to the back in 1995, but she is often mentioned in conversations between Benton Fraser and his colleagues.