Mary Reid Anderson (née Macarthur; 13 August 1880 – 1 January 1921) was a Scottish suffragist (although at odds with the national groups who were willing to let a minority of women gain the franchise) and was a leading trades unionist. She was the general secretary of the Women's Trade Union League and was involved in the formation of the National Federation of Women Workers and National Anti-Sweating League.
In 1910, Macarthur led the women chain makers of Cradley Heath to victory in their fight for a minimum wage and led a strike to force employers to implement the rise.
Around 1901, Macarthur became a trade unionist after hearing a speech made by John Turner about how badly some workers were being treated by their employers. She became secretary of the Ayr branch of the Shop Assistants' Union, and her interest in this union led to her work for the improvement of women's labour conditions. In 1902 Mary became friends with Margaret Bondfield who encouraged her to