He was born at Burnchurch in County Kilkenny, son of Francis Flood and Anne Warden. He was educated at Kilkenny College and the University of Dublin, taking his degree of Bachelor of Arts in 1714. He entered Middle Temple in 1716 and was called to the Irish Bar in 1720.
He was appointed Solicitor-General for Ireland in 1741, Attorney-General for Ireland in 1751, and in 1760 was appointed Chief Justice of the Kings Bench for Ireland. He acted as a judge of assize and was briefly Speaker of the Irish House of Lords. He became the Member of Parliament (MP) for Callan in 1727. He had a town house at Cuffe Street in Dublin and a country house at Farmley in Kilkenny.
He had several children by Isabella Whiteside, but whether the couple were legally married is doubtful. His most famous child, the statesman Henry Flood, who is thought to have been Isabella's son, was generally believed to have been born out of wedlock.
- Leigh Rayment's historical List of Members of the Irish House of Commonscites: Johnston-Liik, Edith Mary (2002). The History of the Irish Parliament 1692-1800 (6 volumes). Ulster Historical Foundation.
- F. Elrington Ball (1897). "Robert Marshall, of Clonmell, Esq". Journal of the Cork Historical and Archaeological Society. III (25): 269. Retrieved 1 January 2011.
- F. Elrington Ball The Judges in Ireland 1221-1921 John Murray London 1926 Vol.2 p.109
- Ball p. 211
- Ball p.221
- Warden Flood (1838). Memoirs of the life and correspondence of the Right Hon. Henry Flood, M.P. John Cumming. p. 7. Retrieved 1 January 2011.
- Ball p.109
|Parliament of Ireland|
| Member of Parliament for Callan
With: Henry Wemys 1727–1751
St George Caulfeild
| Solicitor-General for Ireland
| Attorney-General for Ireland|
| Lord Chief Justice of the King's Bench for Ireland