Lord Decies married Helen Vivien Gould on 7 February 1911.
They had three children:
Eileen Vivien de la Poer Beresford (1912–?)
who married an O'Brien.

Catherine Moya de la Poer Beresford (1913–1967).

Arthur George Marcus Douglas de la Poer Beresford, 6th Baron Decies (1915–1992).

Lady Decies died on 3 February 1931, and following her death he married Elizabeth Wharton Drexel, the daughter of Joseph William Drexel, on 25 May 1936.
Elizabeth had previously been married to Harry Lehr.

Asked how to say his name, Lord Decies told The Literary Digest: "With ci as in conscience it is dee-shees, and Beresford is berysford."
Lord Decies married Helen Vivien Gould on 7 February 1911. They had three children:
Eileen Vivien de la Poer Beresford (1912–?) who married an O'Brien.
Catherine Moya de la Poer Beresford (1913–1967).
Arthur George Marcus Douglas de la Poer Beresford, 6th Baron Decies (1915–1992).
Lady Decies died on 3 February 1931, and following her death he married Elizabeth Wharton Drexel, the daughter of Joseph William Drexel, on 25 May 1936. Elizabeth had previously been married to Harry Lehr.
Asked how to say his name, Lord Decies told The Literary Digest: "With ci as in conscience it is dee-shees, and Beresford is berysford."
John Beresford, 5th Baron Decies