Lilias Torrance Newton was born in 1896 to a prominent Montreal family. She studied with William Brymner at the Art Association of Montreal. During World War I she went to England to work with the Red Cross, and while there studied with Modernist Alfred Wolmark. On her return to Canada she established herself as a professional portrait painter. She was a founding member of the Beaver Hall Group in 1920, sharing a studio at Beaver Hall Hill with Mabel May where she taught art classes. In 1923 she studied in Paris with Alexandre Jacovleff, subsequently returning to the city in 1923, 1929 and 1953.

After her divorce, Torrance Newton found the Depression years of the 1930s difficult, but was able to survive through teaching portrait painting and portrait commissions. Torrance Newton had social connections and was known for her wit, graciousness and sophistication, thus easily created a rapport with the members of the social elite that she painted - such as Vincent and Alice Massey and H.S. Southam. She also painted those in prominent people in the art world - National Gallery director Eric Brown and artists such as Lawren Harris and A.Y. Jackson. During World War II, she was hired by the Department of National Defense to paint Canadian soldiers. By the late 1940s she was considered one of the best portrait painters in Canada, and commissions flowed in from universities, executives of private companies and governments - including one to paint the official portrait of Queen Elizabeth and Prince Philip for Rideau Hall. Her portraits were known for their informality and natural approach to her subject, and were stripped of unnecessary detail to increase the focus on the character of the sitter. Her portraits of women were particularly sensitive.

Torrance Newton was involved with art societies - she was a founding member of the Canadian Group of Painters in 1933, and in 1937 became a full member of the RCA (only the third woman to do so) and showed with them. Among her exhibitions was a 1939 solo show at the Art Assocation of Montreal and a 1940 group show with Group of Seven members Edwin Holgate, A.Y. Jackson and Arthur Lismer at the Art Gallery of Toronto. In 1958 she had a solo exhibition at Victoria College in Toronto.

Torrance Newton continued to travel - in 1946 to the Banff School of Fine Arts, where she painted portraits, in 1953 to Florence, Rome, Paris and Madrid and London in 1957 and 1960. She continued to paint until 1975, and died in 1980 in Cowansville, Quebec.