On 22 November 1859, he married
Lady Louisa Jane Hamilton in London, England. Lady Louisa was the third daughter of
James Hamilton, 1st Duke of Abercorn and
Lady Louisa Jane Russell (daughter of
John Russell, 6th Duke of Bedford). As heir apparent to his father's title, William was already "Earl of Dalkeith" by
courtesy, and thus his new bride was immediately styled "Countess of Dalkeith". They had eight children: •
Walter Henry Montagu Douglas Scott, Earl of Dalkeith (1861–1886) •
Lord Henry Francis Montagu Douglas Scott (1868–1945). in the family crypt of the Buccleuch Memorial Chapel in St. Mary's
Episcopal Church,
Dalkeith, Midlothian. The church is located on Dalkeith's High Street, at the entrance to Dalkeith Country Park. ==Titles, honours and awards==