Cormac K H O’Malley is the son of Ernie O'Malley, Irish author of his autobiographical memoirs, On Another Man’s Wound and The Singing Flame, military historian and militant nationalist from the 1916-1924. Cormac’s mother was Helen Hooker from Connecticut.

Cormac was born in Ireland but came to the US at age 14 to live with his mother after his father died in 1957. After attending Harvard College, serving with the U.S. Navy, and completing Columbia Law School, Cormac worked for ten years in international private law practice in New York and Mexico followed by twenty years as international corporate counsel while living Brussels, London and New York. Since 1999, he has been engaged as an international legal consultant, principally involved in inward investment into Ireland. Cormac has also attended to the publication of his family heritage, and in recent years has co-edited No Surrender Here: The Civil War Papers of Ernie O’Malley, 1922-1924, Broken landscapes: Selected Letters of Ernie O’Malley, 1924-1957, and edited a memoir Rising Out, Sean Connolly of Longford, 1890-1921. More recently he has coedited his father’s military interviews in a series called The Men Will Talk to me: Kerry Interviews by Ernie O’Malley (2012), Galway Interviews (2013) and Mayo Interviews (2014).

Cormac has been interested in Irish history since his college days and in New York he has always been active in Irish American cultural activities, including being President of the Board of Advisors at Glucksman Ireland House, the Centre for Irish and Irish American Studies at New York University. He is helping to organize the Ernie O’Malley Symposium on Modern Ireland and Revolution at Glucksman Ireland House on April 25-26, 2014. He has given his father’s non-nationalist papers to New York University’s Archives of Irish America and his nationalist papers to the University College Dublin Archives.

Cormac lives with his family in Stonington, Connecticut.