Lord Albemarle married Sophia Mary MacNab, a descendant of Loyalist Ephraim Jones and daughter of Sir Allan Napier MacNab, a Joint Premier of the Province of Canada, at Dundurn Castle, Hamilton, Canada, on 15 November 1855.

 Together, they had ten children:
Arnold Keppel, 8th Earl of Albemarle (1858–1942), who married Lady Gertrude Lucia Egerton, only child of Wilbraham Egerton, 1st Earl Egerton of Tatton.

Hon.
Gertrude Mary Keppel (1859–1860), who died in infancy.

Lady Theodora Keppel (c. 1861–1945), who married Colonel Leslie Davidson and had issue.

Hon.
Sir Derek William George Keppel (1863–1944).

Lady Hilda Mary Keppel (1864–1955), who died unmarried.

Lt Col.
Hon.
George Keppel (1865–1947), who married Alice Edmonstone, a long-time mistress of King Edward VII.

Lady Leopoldina Olivia Keppel (1866–1948), who became a nun.

Lady Susan Mary Keppel (1868–1953), who married Sir Walter Townley in 1896.

Lady Mary Stuart Keppel (1869–1906), who married Maj.
Gen. Sir Harold Tagart in 1900.

Lady Florence Cecilia Keppel (1871–1963), who married William Boyle, 12th Earl of Cork in 1902.

Lord Albemarle was received into the Roman Catholic Church on Easter Sunday, 13 April 1879.
He died in August 1894, aged 62, of paralysis, and was buried at Quidenham in Norfolk.
His eldest son Arnold succeeded in the earldom.
The Countess of Albemarle died in April 1917, aged 84.
Lord Albemarle married Sophia Mary MacNab, a descendant of Loyalist Ephraim Jones and daughter of Sir Allan Napier MacNab, a Joint Premier of the Province of Canada, at Dundurn Castle, Hamilton, Canada, on 15 November 1855.
 Together, they had ten children:
Arnold Keppel, 8th Earl of Albemarle (1858–1942), who married Lady Gertrude Lucia Egerton, only child of Wilbraham Egerton, 1st Earl Egerton of Tatton.
Hon. Gertrude Mary Keppel (1859–1860), who died in infancy.
Lady Theodora Keppel (c. 1861–1945), who married Colonel Leslie Davidson and had issue.
Hon. Sir Derek William George Keppel (1863–1944).
Lady Hilda Mary Keppel (1864–1955), who died unmarried.
Lt Col. Hon. George Keppel (1865–1947), who married Alice Edmonstone, a long-time mistress of King Edward VII.
Lady Leopoldina Olivia Keppel (1866–1948), who became a nun.
Lady Susan Mary Keppel (1868–1953), who married Sir Walter Townley in 1896.
Lady Mary Stuart Keppel (1869–1906), who married Maj. Gen. Sir Harold Tagart in 1900.
Lady Florence Cecilia Keppel (1871–1963), who married William Boyle, 12th Earl of Cork in 1902.
Lord Albemarle was received into the Roman Catholic Church on Easter Sunday, 13 April 1879. He died in August 1894, aged 62, of paralysis, and was buried at Quidenham in Norfolk. His eldest son Arnold succeeded in the earldom. The Countess of Albemarle died in April 1917, aged 84.
William Keppel, 7th Earl of Albemarle