Kathleen Morris was born in 1893, to a middle-class family in Montreal. She stayed for a time in the home of her mothers cousin, the artist Robert Harris. During her stay with them, he did a drawing of her which sparked an interest in drawing. She received encouragement from Harris and she enrolled at the Art Association of Montreal in 1907. She also participated in Maurice Cullens summer landscape painting classes. She exhibited for the first time at the AAMs annual Spring Exhibition in 1914. Two years later she began to exhibit with the Royal Canadian Academy.
The First World War intervened in the studies of AAM students. Kathleen left the AAM in 1917, and her brother,Jim, served overseas with the the Black Watch regiment. She moved to Ottawa with her mother in 1923, but returned to Quebec for annual winter sketching trips in Berthierville. Through her friends and fellow AAM alumni, Morris was invited to become part of the Beaver Hall women group. She was elected an Associate of the RCA in 1929, the same year she returned to Montreal permanently.
She exhibited extensively. Her first solo exhibition was at the Art Association of Montreals Print Room, in 1939. Two years later she participated in an exhibition with Mabel Lockerby, Pegi Nicol-Macleod and Marian Scott at the Art Gallery of Toronto. Another solo exhibition followed in 1945, at the Harris Memorial Gallery, in Charlottetown. Another Beaver Hall women group exhibition came in 1950, at the Montreal Museum of Fine Art. Her last solo exhibition took place in 1976, at Walter Klinkhoff Gallery.
On seeing her work in a 1962 exhibition at the Arts Club, Montreal, Dorothy Pfeiffer, arts writer for the Montreal Gazette, wrote, No one could observe this cheery work without feeling a sense of participation, as if watching the scene from a hidden window. Such painting…is technically authoritative, the personal expression of the joy of life…by a gifted, forthright, fearless artist. Elected a member of the Canadian Group of Painters in 1940, her work is represented in the collections of the National Gallery of Canada; the Montreal Museum of Fine Arts; the Art Gallery of Hamilton, Ont; and the UofT to mention a few. She died in 1986 at the age of 93.