Florence Ada Custance was a trade unionist and labour organizer who helped found a number of socialist organizations in Canada, including a local Plebs League, the Ontario Labour College, the Socialist Party of North America, and the Communist Party of Canada.

She was heavily involved in cultivating chapters of the Women's Labour League across Canada and edited the federation's monthly periodical, The Woman Worker, which ran from 1926 through to her death in 1929.

Along with Bill Moriarty, Tim Bell and Maurice Spector, Custance helped found and operated a local Plebs' League, a precursor to the Communist Party of Canada.

[3] Local newspapers covered Constance's international travel and speaking engagements in Chicago, Germany, and Russia where she spoke at workers' conferences.

[14] Through the publication and her work as secretary of the Federation, she wielded considerable influence over the chapters, some argue more than the CPC leadership was ever able to assert.

[16][17] As editor of The Woman Worker, and as a public figure in Toronto labour circles, she is described as one historian as "one of the strongest intellectuals in the Party.

"[15] In her role as editor and public speaker, she was able to put forward issues and stories of interest to working-class women, including: access to birth control,[18][15][19] minimum wage abuse,[20] wrongful dismissal,[21] wafe theft,[13] and the criminalization of poverty and mental illness.

[13] She was removed as editor of The Woman Worker and from her role on the Canadian Labour Defense League in January 1929, with the publication citing an unspecified illness.

[27][28][29][30] When she attempted to run for school trustee in 1926, she was disqualified (along with another candidate, Mrs. Adelaide Blumptree) as they both were not listed on assessment rolls in their districts.