Sir Charles was married on 7 December 1866 to Harriet Sarah Moncreiffe (7 February 1848 – 9 May 1906), daughter of a Scottish baronet.
His uncle, Sir Charles Mordaunt, 10th Baronet, was involved in a sensational divorce case of 1870 that concerned, among other things, a possible relationship between his wife Harriet and the Prince of Wales.
Harriet Beecher Stowe | Harriet Tubman | Harriet Martineau | Harriet Smithson | John Mordaunt, 1st Earl of Peterborough | Harriet Harman | Harriet Walter | Harriet Taylor Mill | Harriet Miers | Henry Mordaunt, 2nd Earl of Peterborough | Harriet Thorpe | Harriet Mordaunt | Harriet Cohen International Music Award | 'Harriet' | John Mordaunt, 1st Baron Mordaunt | Harriet Smith Windsor | Harriet Randolph Hyatt Mayor | Harriet Monroe | Harriet Klausner | Harriet Arbuthnot | Harriet A. Hall | Harriet Adams | Thomas Osbert Mordaunt | Sir Charles Mordaunt | Osbert Mordaunt | Mount Harriet National Park | Julia Jekyll and Harriet Hyde | J. Mordaunt Crook | Harriet Winslow | Harriet Werley |
The following year he was cited as one of two co-respondents in the case for divorce brought by Sir Charles Mordaunt, 10th Bt., a former M.P., against his wife, Harriet, in which Prince Albert Edward, The Prince of Wales (later King Edward VII), was called to give evidence.