He was born in Edinburgh on 16 December 1775 one of 12 children and second son of Isabella and William Fullerton Esq of Carstairs.

He was raised in a large house on Nicolson Street in Edinburgh's Southside.

[1] His elder sister Elizabeth married William Fullerton-Elphinstone a Director of the East India Company.

He then lived at 27 Melville Street in a newly built townhouse in Edinburgh's west end.

[4] In the Disruption of 1843 Fullerton spoke largely in the defence of the established Church of Scotland within the lengthy legal debates.