He married Mary Frances Farmer (10 August 1857 – 18 May 1929) daughter of Reginald Onslow Farmer (1828–1904) on 22 August 1876 at Hatfield Hertfordshire. They had six children:[2]
Henry Cornelius O'Callaghan Prittie (19 July 1877 – 3 May 1948) the 5th Baron Dunalley
Maura Geraldine Anne Prittie (2 September 1879 – 19 May 1880)
Francis Reginald Dennis Prittie (15 October 1880 – 19 December 1914)
Kathleen Everilda Prittie (13 April 1882 – 27 April 1910)
Mary Prittie (b. 24 January 1885)
Irene Rose Prittie (24 April 1887 – 2 November 1887)
Coat of arms of Henry Prittie, 4th Baron Dunalley
Crest
A wolf's head erased Or.
Escutcheon
Per pale Argent and Gules three wolves' heads erased Or.
Supporters
Dexter a man in armour Proper holding a tilting spear in the right hand. Sinister a stag Proper attired unguled collared and chained Or.