Cora Harrison was born in County Cork in Southern Ireland and was educated in Cork city. After graduating from the National University of Ireland with a degree in French & German, she went to London and worked as a Personal Assistant to the Managing Director of the Linguaphone Institute (language teaching through the audio-visual method).
She married and had two children, staying at home with them until they were school age, and then started teaching. She was a teacher for twenty-five years ten of which were spent as a headteacher. During these years she and her husband bought a small farm of twenty acres (with an Iron Age fort, stone cottage and river), which they used as a holiday cottage until they retired. Inspired by this place, she began writing books after her retirement, starting with the seventeen books in the Drumshee Timeline series, which told the history of Ireland through the lives of the people who lived on the little farm, from Iron Age times right up to the present.
In 2007 she wrote her first book for adults the first in a series of detective stories which were placed on the nearby area known as the Burren, whose history and landscape form the background to her 'Mara the Brehon' series.