O'Connell was born in the South Bronx district of New York City, one of five children whose parents were Irish immigrants.
When she finished school, she pursued her interest in theatre studying first at Erwin Piscator's Dramatic Workshop, New York City, and later at the Actors Studio run by Lee Strasberg.
In her early twenties, O'Connell moved to Dublin, Ireland, where she set up the Stanislavski Studio at the Pocket Theatre.
She married the Irish singer Luke Kelly in June 1965,[1] but they separated in the early 1970s.
[2] O'Connell died of cancer at her home in Dublin at the age of 61 and is buried in Glasnevin Cemetery.