Frances Isabelle Parnell (4 September 1848 – 20 July 1882) was an Irish poet and Irish nationalist. She was the sister of Charles Stewart Parnell and Anna Catherine Parnell, important figures in 19th-century Ireland.

Parnell was born on 4 September 1848 in Avondale, County Wicklow, Ireland into a wealthy Protestant background. She was the eighth of eleven children born to John Henry Parnell, a landowner and the grandson of the last Chancellor of the Irish Exchequer, and Delia Tudor Stewart Parnell, an Irish-American and the daughter of Admiral Charles Stewart (1778–1869) of the US Navy. Parnell's mother hated British rule in Ireland, a view presented through her children's works.

As a child, Parnell studied mathematics, chemistry, and astronomy, and she could fluently speak and write in several European languages. She also had talents in music, painting, and drawing.^{[citation needed]}

Parnell's parents separated when she was young, and soon after her father died in July 1859, she and her mother moved to Dalkey. A year later they moved to Dublin. In 1865, they moved to Paris to join her mother's brother. Parnell and her mother were still in Paris when the Franco-Prussian War broke out in 1870; they joined the American Ladies' Committee. They nursed the wounded, and fund-raised for and set up a hospital, including overseeing the purchasing and storing of supplies.

In 1874, Delia's brother died, and she and Parnell left Paris to return to the family estate in Bordentown, New Jersey in the United States, where Parnell's political career began.

Now are you men or cattle then, you tillers of the soil?

Would you be free, or evermore in rich men's service toil?

The shadow of the dial hangs dark that points the fatal hour