Marcus Hugh Tristram de la Poer Beresford, 7th Baron Decies (born 5 August 1948), is an Anglo-Irish hereditary peer.

[4][3] His paternal grandfather was John Beresford, 5th Baron Decies,[5] an Irish representative peer who married two American heiresses, his grandmother Helen Gould (daughter of American railroad executive George Jay Gould I),[6][7][8] and after her death, Elizabeth Wharton Drexel (a daughter of Joseph William Drexel, who had previously been married to Harry Lehr).

[9] When asked how to pronounce his name, his grandfather Lord Decies told The Literary Digest: "With ci as in conscience it is dee-shees, and Beresford is berysford.

Beresford practiced as a solicitor and rose to be Chairman of A&L Goodbody, the leading Irish corporate law firm.

[14][15][failed verification] He is chairman of the trustees of the British Cemetery, Elvas,[citation needed] a member of the Friends of the Lines of Torres Vedras and the Waterford Historical Society.