[1] She moved to Jamaica as a small child, and attended Mount Alvernia High School in Montego Bay.
She was Jamaica's Rhodes Scholar for 1978, the first woman to be selected for the honour, and subsequently completed a Master of Letters degree at Wolfson College, Oxford.
She later completed a doctorate at the University of the West Indies (UWI), with her thesis being supervised by Edward Baugh.
[1] O'Callaghan initially worked as a junior lecturer in English literature at the UWI campus in Mona, Jamaica.
O'Callaghan is the current dean of the Faculty of Humanities and Education, and has previously served as head of the Department of Language, Linguistics and Literature.