Onésime Dorval is Saskatchewan's first officially certified teacher, and her work and service marked the establishment of French and English education in the province. Born and raised in St. Jérôme, Quebec, Dorval had wanted to join the order of the Sisters of Good Shepherd in New York, but owing to her frail health she was not allowed to make her final vows. During her postulate and noviciate, she learned English and remained determined to serve the Church. She responded to the call of Bishop Vital Grandin, OMI, of St. Albert, who was recruiting resourceful women as housekeepers and teachers for Roman Catholic missions of the North-West. In 1877, Dorval journeyed west to teach in the Red River settlement of Fort Garry. In the summer of 1880, she made another arduous journey by Red River cart to St. Laurent de Grandin. Between 1881 and 1883 she made her way to St. Albert, next to Ste. Anne, and then back to St. Laurent de Grandin, which was soon to be Saskatchewan territory. She spent many hours teaching and performing religious duties with the Métis and French communities of St. Albert (Alberta), St. Laurent (Saskatchewan), and Ste. Anne (Manitoba). Her kindness, piety and great memory won her the admiration of many; she was also a resourceful teacher, who loved and respected her Métis students. While in St. Laurent, she contributed to the establishment of a grotto to Our Lady of Lourdes.
She then moved to Battleford and started another school, where she taught until 1896. She moved again, and taught in a one-room school in the Batoche No. 1 School District from 1896 until 1914. In 1913, St. Michael's School held a celebration to mark her fifty years of teaching. During this time, she also worked as a housekeeper and provided board for children who lived outside walking distance to school. From there, Dorval taught in Aldina for one year before returning to St. Laurent de Grandin, as French teachers there were in short supply. After retiring from teaching in 1921 with the Sisters of Presentation in Duck Lake, she continued her community and missionary activities and wrote her memoirs. She died in Rosthern on December 10, 1932, at the age of 87, and is buried in the cemetery of St. Michael's School in Duck Lake.
The government named four small islands in her honour in the North Saskatchewan River near North Battleford. In 1954, Dorval was designated a person of national historic significance by the National Historic Sites and Monuments Board of Canada. In commemoration of her life and work, a bronze plaque was presented to the Batoche Museum. In 1994 the Division scolaire francophone #310 (see French Education) instituted its first Prix Onésime Dorval, and since then the Association des directions d'écoles fransaskoises has annually recognized its teachers who have exemplified the hard work and dedication of Onésime Dorval. When Parks Canada made women's history a priority, another plaque in her honour was unveiled in Duck Lake on October 29, 2002.