Sarah Margaret Armour Robertson (June 16, 1891 – December 6, 1948) was a Canadian painter of landscapes, still lifes, portraits, and murals for private homes.

World War I interrupted her studies, after which she continued them from 1921 to 1924 under Randolph Hewton, a founding member of the Canadian Group of Painters, and Wood Scholarship winner.

[2] During her last few years at the Art Association, Robertson joined former and current students, and fellow artists, along with her teacher Randolph Hewton, in the Beaver Hall Group.

Nora Collyer, Emily Coonan, Prudence Heward, Mabel Lockerby, Mabel May, Kathleen Morris, Lilias Torrance Newton, Sarah Robertson, Anne Savage and Ethel Seath were part of this group, sometimes known the Beaver Hall Hill Group or Beaver Hall Women.

By the end of 1921, the Beaver Hall group ran into serious financial difficulties which necessitated relinquishing their studios.

Robertson's paintings appeared in exhibitions of Canadian art at Wembley, England, in 1924 and 1925 and she was invited to participate in shows by the Group of Seven in 1928, 1930 and 1931.