William Grinsell Nicholl (London 1796–1871) was a British 19th-century architectural and monumental sculptor.

His studio was on Grafton Street East - off Tottenham Court Road, London The Oxford Dictionary of National Biography incorrectly states that in about 1849 he adopted his maternal grandchild, Elisabeth Nicholl who aged eleven had become an orphan.

On 19 October 1865 an Elizabeth Clara White born 22 January 1838 underwent an adult baptism at St Giles in the Fields, London, giving her parents names as William Grinsell & Elizabeth and the family name Nicholl.

[3] Elizabeth White married, using her correct name, a wealthy man called Guppy and witnessed the will of William Grinsell Nicholl one week before he died in the family home in Churchfield Road, Acton, west London on 8 December 1871.

Nicholl's second daughter, Charlotte Anne (1824-1905), married John Russell an iron founder, 17 February 1855 in St James Church, Sydney and their son John Peter Russell, the Australian impressionist painter, was born in 1858.