Family and personal life
In 1858 Nicholson married Isabella Sarah Meek (died 1934), only daughter of Master Distiller John Meek, by whom he had 14 children:
Colonel the Rt Hon. William Graham Nicholson , MP for Petersfield from 1897 to 1935
Brigadier-General John Sanctuary Nicholson , MP for Westminster (Abbey) from 1921 to 1924
Lieutenant-Colonel Arthur Carleton Nicholson (1864–1945), High Sheriff of Wiltshire, who married Susan Dumaresq (died 1966), leaving issue
Richard Francis Nicholson (1865–1940), of Woodcott House, Hampshire, who married Helen Portal (died 1927), elder daughter of the Revd Canon George Portal, having issue:
Brigadier Claude Nicholson , who married the Hon. Ursula Hanbury-Tracy (died 1977), only daughter of Major the Hon. Algernon Hanbury-Tracy and sister of the 6th Baron Sudeley, leaving issue
Sir Godfrey Nicholson, 1st Baronet, who married Lady Katharine Lindsay (died 1972), having issue:
Rose Nicholson, Lady Luce (died 2023)
Laura Nicholson, Lady Montgomery-Cuninghame (died 2021)
Emma Nicholson, Baroness Nicholson of Winterbourne
Harriet Nicholson, married Charles Flower, a great-grandson of James Hamilton, 1st Duke of Abercorn, and great-great-nephew of Cyril Flower, 1st Baron Battersea
Major Hugh Blomfield Nicholson (1866–1957), of Mapperton Manor, High Sheriff of Dorset, who married Kathleen Burke (died 1936) and Eileen Dorothy Northey (died 1968), without issue
Major Reginald Nicholson (1867–1952), High Sheriff of Hampshire, who married Lady Laura Knowles (died 1959), younger daughter of the 9th Earl Waldegrave, having issue:
Godfrey Maule Nicholson (1872–1901)
Captain Clement Octavius Edward Nicholson (1874–1930), who married Hilda Ohlsson (div. 1911) and Judith Burnaby-Atkins (died 1951), without issue
Ellen Isabel Nicholson, married the Revd Preb. Edward Bernard (1842–1921), of High Hall, near Wimborne, Dorset
Edith Mary Nicholson, married Colonel Sir Edward Bradford, 1st Baronet
Isabel Winifred Nicholson (died unmarried 1959)
Mary Stephanie Nicholson , married Lieutenant-Colonel Henry Ridley (1851–1931)
Gertrude Ann Nicholson, married Lieutenant-Colonel George Anson (1848–1916)
Marion Theodora Nicholson, married Major Edward Talbot-Ponsonby (1872–1946).
Nicholson was seated at Basing Park near Alton, Hampshire (purchased from Joseph Martineau in 1863), and died in 1909 at his townhouse in South Audley Street, London.