The second son of Denis O'Conor, O'Conor Don and the brother of Charles Owen O'Conor, O'Conor Don, Denis Maurice O'Conor was educated at Downside School and the University of London, graduating MA in 1861 and LLD in 1866. He was called to the bar by the Middle Temple in Easter Term, 1866. A magistrate for County Roscommon, he was High Sheriff of Roscommon for 1865.
- "Obituary". The Times. 27 July 1883. p. 5.
- Burke, Bernard. A genealogical and heraldic history of the landed gentry of Great Britain & Ireland (Volume 2). ebooks