Mark de Blacam studied legal science and politics and economics at Trinity College Dublin. He began practice at the Bar in 1977 and was called to the Inner Bar in 1999. He has written many articles published in legal journals. His book Judicial Review was first published in 2001; its third edition won the prize for Law Book of the Year in 2018. Mark de Blacam lives in Dublin with his wife Grainne and their six springer spaniels.