The facts concerning Menken's early life are obscured by later and confused publicity stories. On various occasions she claimed various original names, birthplaces, and histories. It seems likely that her family at some time in her childhood moved to New Orleans, Louisiana. She displayed an early talent for singing and dancing, and she later claimed that in her youth she rode horses in a circus, modeled for a sculptor, and danced in the New Orleans French Opera House. She married Alexander Isaac Menken in Livingston, Texas, in 1856 and thereafter retained his name on the stage through several short-lived marriages. She appeared on the stage at Shreveport, Louisiana, in The Lady of Lyons as early as 1857 and made her debut in New Orleans the same year in Fazio. She began to publish verse about that time; several poems appeared in the Cincinnati Israelite during 1857–59 and in the New York Sunday Mercury in 1860–61.

Menken's fame preceded her to London, where she opened in Mazeppa in 1864. Her literary entourage there soon included Charles Dickens, Algernon Swinburne, and Dante Gabriel Rossetti. In 1865 she had a run in New York City and the following year another, and she made a successful United States tour before returning to Europe in 1866. Everywhere she played before record audiences. Her performances in such pieces as Dick Turpin, The French Spy, Three Fast Women, and The Child of the Sun were generally respectfully received, but always the demand was for Mazeppa. She performed extensively in Paris and in Vienna, returning to London in 1867. She gave what proved to be her last performance at the Sadler's Wells Theatre in May 1868. Eight days after her death her Infelicia, a collection of poems that was dedicated to Dickens, was published in London.