He married on June 26, 1895, Almina Victoria Maria Alexandra Wombwell, daughter of Marie Boyer, the wife of Frederick Charles Wombwell, possibly by Alfred Rothschild.
Their grandson, Henry George Reginald Molyneux Herbert, 7th Earl of the Town and County of Carnarvon, has been Racing Manager to Queen Elizabeth II since 1969, and one of Her Majesty's closest friends
The 5th Earl was an enthusiastic amateur Egyptologist. In 1907 he undertook to sponsor the excavation of the royal tombs at Thebes by Howard Carter. It was in 1922 that they opened the tomb of Tutankhamun in the Valley of the Kings, exposing treasures that are unsurpassed in the history of archaeology. A few months later, Carnarvon died suddenly, giving credence to the story of the "Curse of Tutankhamun". His companion, Howard Carter, lived for another seventeen years.