Highway was born on his father's trap-line, on a remote island on Maria Lake, in northern Manitoba, 100 miles north of the Brochet reserve. For the first six years of his life, he lived in northwestern Manitoba speaking only Cree. He had a difficult childhood in a family of twelve children (of whom only 5 survive). He helped his father, a fisherman, working from dawn to dusk.
At the age of 6, Tomson began to speak English (becoming fluent in his late teens) and was sent to a Roman Catholic boarding school, the Guy Hill Indian Residential School, where he stayed until he turned 15. His life there, which included sexual abuse at the hands of the priests who ran the school, coloured (and tainted) his own life and art and that of his brother's, dancer/choreographer René (with whom Tomson often worked and who died of AIDS in 1990).
He subsequently went to high school in Winnipeg, living with several white families. In 1975 he completed his studies in music at the University of Western Ontario and became an accomplished pianist. He lived for a time in England, rubbing shoulders with the "elite" in cultural life. For some reason he dropped that life like a hot potato. To complete a BA, he took a minor in English and met James Reaney. For the next years he worked for many aboriginal organizations as a social worker which allowed him to travel across the country and to learn about the problems of many of Canada's First Nationals.
At age 30, Tomson decided to describe what he saw and felt that the theatre had traditions that were similar to the aboriginal cultural experience (oral history). His first plays were performed to mostly native audiences on reserves and in urban community centers.
In addition to his writing, Tomson worked with other Native theater companies in various capacities (actor, musical director, director, etc.), touring Indian reserves far and wide. Despite the fact that his first language is Cree, Tomson's plays are in a lyrical,occasionally haunting, English.
The Rez Sisters hit the big time in Toronto theater in 1986, and a few years later, Dry Lips Oughta Move to Kapuskasing premiered. Tomson is also the author of the novel, The Kiss of the Fur Queen, on the Canadian best seller list for seven weeks.
He served on the faculty of the Native Theatre School and, from 1986 to 1992 he was artistic director of Native Earth Performing Arts (NEPA), an organization dedicated to the promotion of aboriginal theatre. In 1994 he was inducted into the Order of Canada, the first aboriginal writer to be so honoured.