In 1900, in middle age, Sargant married Amelia Julia, eldest daughter of Dion Gambardella, civil engineer; they had one son and two daughters. He was knighted (Knight Bachelor) in 1913.
He died at his home, 21 Madingley Road, Cambridge, on 23 July 1942. He is buried in the Parish of the Ascension Burial Ground in Cambridge; the plot number is 1H12. His grave is mentioned in Lucy Joan Slater's "A Walk round the Ascension Burial Ground, formerly known as St. Giles' Cemetery", fourth edition, December 1994.
- ‘SARGANT, Rt Hon. Sir Charles Henry’, Who Was Who, A & C Black, an imprint of Bloomsbury Publishing plc, 1920–2008; online edn, Oxford University Press, Dec 2012 ; online edn, Oct 2012 accessed 28 Feb 2013