William Brymner was born in 1855 in Greenock, Scotland. He studied at the Académie Julian in Paris.
With financial support from his father, Brymner sailed for Europe in February 1878 to study architecture. He lived in Paris, where initially he worked as an exhibition designer for the Canadian commissioner for the universal exposition held there that year. The following summer he took drawing lessons with Charles-François Pinot. Later he enrolled at the Académie Julian, studying with Jules-Joseph Lefebvre and Gustave Boulanger. Now fully committed to painting, Brymner continued his studies at Académie Julian until 1880 with Tony Robert-Fleury and Adolphe-William Bouguereau. In April 1879 he had begun independent studies with Charles Durand, known as Carolus-Duran, and he supplemented his studies with addtional anatomy courses at the École des Beaux-Arts. Brymner embraced French academic techniques such as tenets good draftsmanship, and formal harmony, but refused to embrace what he called artificial studio-produced academic painting.
Brymner affiliated himself with a group of contemporary naturalist painters inspired by the Barbizon School, and led by Jean-François Millet, adopted their practice of sketching in rural settings in a quest for picturesque subjects and natural effects. During the summer of 1879 he painted in the French and Belgian countryside.
Brymner returned to Ottawa in the summer of 1880 and accepted the position of headmaster at the new Ottawa Art School. Brymner strove to create spaces where artists of all disciplines could gather and exchange ideas. In 1886 he settled in Montréal, where he taught for thirty-five years at the Art Association of Montréal. Among his students were painters A.Y. Jackson and Clarence Gagnon.
He was an influential art teacher and painter creating magnificant figures and landscapes. He painted directly from nature, in the style of the French Barbizon school. Always experimenting with different techniques and viewpoints, he often chose Canadian subjects, such as rural Québec. The Canadian Pacific Railway commissioned Brymner to produce a series of paintings promoting the scenic views of the Canadian West. He won a gold medal at the Pan-American Exposition in Buffalo in 1901, and silver at the Louisiana Purchase Exposition in 1904. In 1916, Brymner was made a companion of the Order of Saint Michael and Saint George.
He served as president of the Royal Canadian Academy for nine years. He also worked with the Canadian Art Club, the Pen and Pencil Club of Montreal, and the Arts Club of Montreal. He travelled frequently through Europe and Quebec’s Eastern Townships, setting up a studio in Saint-Eustache with fellow artist Maurice Cullen.
Brymner died in June 1925 in Wallasey, England, and was buried there.