Cicely Mary Hamilton (née Hammill; 15 June 1872 – 6 December 1952), was an English actress, writer, journalist, suffragist and feminist, part of the struggle for women's suffrage in the United Kingdom.

She is now best known for the feminist play How the Vote was Won, which sees a male anti-suffragist change his mind when the women in his life go on strike.

This grew to around 400 members, including Ivy Compton-Burnett, Sarah Grand, Violet Hunt, Marie Belloc Lowndes, Alice Meynell, Olive Schreiner, Evelyn Sharp, May Sinclair, and Margaret L. Woods.

[7] In the days before radio, one effective way to get a message out into society and to have it discussed was to produce short plays that could be performed around the country, and so suffrage drama was born.

[11] Hamilton inspired young schoolgirls, supportive of suffrage, like Winifred Starbuck, who had Hamilton and other leaders' pictures on her desk in purple, white and green frames and later herself protested by school disorder, such as graffiti and hiding the school registers and handbell, as a milder form of resistance to authority for women's suffrage.

[7] During World War I, Hamilton initially worked in the organisation of nursing care, with the Scottish Women's ambulance service near Paris,[7] and then joined the army as an auxiliary.

After the war, she wrote as a freelance journalist, particularly on birth control, and was a press officer for the Geneva International Suffrage Conference[7] and as a playwright for the Birmingham Repertory Company.

[12] Hamilton was a regular contributor to Time and Tide magazine, and an active member of the feminist Six Point Group, campaigning for the rights of children, widows and unmarried mothers; equal guardianship of children, and equal pay in teaching and civil service.