Personal life
On 5 August 1786, William was married to Lady Sarah Windsor, daughter of Other Windsor, 4th Earl of Plymouth and the former Hon. Catherine Archer (daughter of Thomas Archer, 1st Baron Archer). Together, they were the parents of five sons (three of whom died before him) and five daughters (two of whom died before him), including:
Claude Champion de Crespigny (c. 1787–1813), a Lieutenant in the Royal Navy who died in Palermo, Sicily in 1813.
William Other Robert Champion de Crespigny (1789–1816), an officer in the Royal Navy who died while on active service in 1816.
Augustus James Champion de Crespigny (1791–1825), an officer in the Royal Navy who died from yellow fever on board the HMS Scylla in 1825; he married Caroline Smijth, daughter of Sir William Smijth, 7th Baronet, in 1817.
Sarah Champion de Crespigny (1792–1805), who died in youth.
Frances Champion de Crespigny (1793–c. 1794), who died in infancy.
Heaton Champion de Crespigny (1796–1858), the vicar of Neatishead who married Caroline Bathurst, daughter of Rt. Rev. Dr. Henry Bathurst, in 1820.
Mary Catherine Champion de Crespigny (1798–1858), who married Rev. John Brigstocke in 1830.
Patience Anne Champion de Crespigny (c. 1800–1831), who married Rev. Hon. Paul Anthony Irby, son of Frederick Irby, 2nd Baron Boston, in 1814.
Emma Honoria Dorothy Champion de Crespigny (1800–1883), who died unmarried.
Herbert Joseph Champion de Crespigny (1806–1881), who married Caroline Smijth, his elder brother Augustus' widow, in 1831.
Lady Sarah died in December 1825. Sir William died on 28 December 1829. By his will, dated 27 February 1829, the proceeds from the sale of his leasehold estates and the residue of his personal estate, sworn under £14,000, was distributed among his surviving children. As his eldest surviving son predeceased him, baronetcy and entrusted family properties passed to his grandson, Claude.
