Before inheriting the earldom, Pleydell-Bouverie married Julian Eleanor Adelaide Balfour, daughter of Charles Balfour (himself great-grandson of
Robert Balfour, 4th of Balbirnie and nephew of
Robert Balfour, 6th of Balbirnie and Scottish
nabob James Balfour), on 20 January 1891, and they had ten children: • Lady Jeane Pleydell-Bouverie (23 March 1892 – 1976), married Maj. (George) Gerald Petherick (d. 1946) in 1914 and had issue. • Lady Katherine Pleydell-Bouverie (16 May 1894 – 12 November 1961), married John Henry McNeile. •
William Pleydell-Bouverie, 7th Earl of Radnor (1895–1968) • Lady
Elizabeth Pleydell-Bouverie (27 June 1897 – 7 July 1982) • Capt. Hon. Edward Pleydell-Bouverie (10 September 1899 – 7 May 1951), married Alice Pearl Crake, widow of
2nd Baron Montagu of Beaulieu, and had issue. • Maj. Hon. Bartholomew Pleydell-Bouverie (6 April 1902 – 31 October 1965), married firstly Lady Doreen Clare Hely-Hutchinson, daughter of the
6th Earl of Donoughmore, and had issue and secondly with Katharine Tod. • Lady Margaret Pleydell-Bouverie (26 June 1903 – 17 September 2002), married Lt.-Col
Gerald Barry and had issue. • Hon. Anthony Pleydell-Bouverie (26 March 1905 – 25 June 1961), married Anita Estelle Costiander. • Lady Helen Pleydell-Bouverie, OBE (2 January 1908 – 2003), married on 22 July 1931 Lt.-Col Hon.
David John Smith, son of the
2nd Viscount Hambleden, and had issue. • Hon. Peter Pleydell-Bouverie (19 October 1909 – 1981), married firstly
Audrey Evelyn James and secondly Audrey Kidston and had issue by the latter. ==Coat of arms==