Eliza Cook was the youngest of the eleven children of a brasier living in London Road, Southwark. When she was about nine years old her father retired from business, and the family went to live at a small farm in St. Leonard's Forest, near Horsham. Her mother encouraged Eliza's fondness for imaginative literature, but the child was almost entirely self-educated. She began to write verses before she was fifteen ; indeed, some of her most popular poems, such as 'I'm afloat' and the 'Star of Glengarry,' were composed in her girlhood. 
She was a regular columnist for the Weekly Dispatch, a newspaper owned at the time by James Harmer, a London Alderman. She lived for a time at James Harmer's residence, Ingress Abbey, in Greenhithe, Kent, and wrote certain of her works there. She was a close friend of American actress Charlotte Cushman.
Eliza Cook was a proponent of political freedom for women, and believed in the ideology of self-improvement through education, something she called "levelling up." This made her hugely popular with the working class public in both England and America.