 O'Connell was born in Donoughmore, County Cork, then part of the United Kingdom of Great Britain and Ireland, the son of Michael O'Connell and his wife Bridget, née O'Connell.His family soon emigrated to the United States and settled in Columbia, South Carolina, where his father's two brothers, Jeremiah and Joseph, were serving as missionary priests.As a young man, O'Connell felt called to be a priest and entered St. Charles College, Ellicott City, Maryland in 1868.