He married Helen Anne Cochran Macadam on 1 November 1887 at Duddingston Parish Church, Edinburgh.
The principal branches of the Clan Dundas were Dundas of Blair Castle, Dundas of Arniston, Dundas of Duddingston and Dundas of Fingask.
The lands of Duddingston were purchased by James Hamilton, 8th Earl of Abercorn (1712–1789), in 1745 from the Duke of Argyll.
He repurchased some of the family's ancestral lands in Scotland, which had been dissipated during their long tenure in Ireland, including the feudal barony of Duddingston in Edinburgh, and Paisley Abbey.