She first became active in the farm movement as womenís district director of the United Farmers of Canada (Saskatchewan section), helping organize the first Farm Womenís Week at the University of Saskatchewan in 1928. She served as president of the womenís section of UFC from 194549. In 1949 when the UFC was reorganized to become the Saskatchewan Farmers Union, Mrs. Hart was elected first womenís president, a position she held for two years.

Through her career Elsie Hart was a strong advocate of better medical care programs. She was active in the State Hospital and Medical League. Later she was appointed by the provincial government to the Saskatchewan Health Planning Commission which recommended introduction of Saskatchewanís universal hospital and medical care insurance programs. She encouraged other women to work for provincial health programs and raise money to finance medical scholarships and buy equipment for the University of Saskatchewan in its fight against cancer.

Active in the co-operative movement, Elsie Hart was a charter member of the Saskatchewan Co-operative Womenís Guild, organized in 1940. In 1945 she was appointed a member of Saskatchewanís first labor relations board, and served in that capacity until 1964. The University of Saskatchewan appointed her to its college of agriculture advisory committee. An honorary doctor of laws degree was conferred on her in 1973 by the University of Saskatchewan for her contributions to Saskatchewan and Canada.