John Isatt was the son of John Isatt and Mary née Hood of London who were married at St. Pancras in 1810.
John Isatt was appointed to the position of Assistant Surgeon on 7 July 1813. He was on the list of surgical pupils who trained at Middlesex Hospital between the years 1810 to 1818. His status was that of House Surgeon.
He was appointed assistant-surgeon to the Blenheim in 1813, assistant-surgeon on the Creole in 1818 and assistant-surgeon to the Sybille in 1819 and on the Gloucester in 1822 
In 1824 he was appointed as surgeon to the Isis . In 1825 to the Scout 
He was appointed surgeon to the Brisk and was on the list of men who were wounded in action on vessels commanded by Vice-Admiral Sir Edward Codrington K.C.B., during a conflict with the Turkish Fleet in Navarin Harbour on 20 October 1827. His injuries were considered slight.
He was appointed as surgeon to the Barham in 1831
His only appointment to a convict ship was to the Susan in 1834. The Susan departed London on 10th March 1834.
John Isatt died at sea off the coast of Portugal while on this voyage. The ship endeavoured to put into the Tagus, to procure another medical superintendent, but easterly winds compelled her to bear up for Madeira and Rio Janeiro. 
Archibald Ross joined the vessel as John Isatt's replacement at Madeira.
In his Will surgeon John Isatt left his estate to his mother Mary Isatt, widow of 48 Drummond Street, Euston, London, and his three sisters Jane (bap. 1801), Mary(1805) and Eliza (b. 1808). 
John Isaett's father John Isatt senior, died at Euston, London the previous December (1833) aged 80.
 The History of the Middlesex Hospital During the First Century of Its Existence By Sir Erasmus Wilson p.253
 The Morning Chronicle 6 July 1822
 Caledonia Mercury 23 January 1824
 Hamshire Telegraph and Sussex Chronicle 11 April 1825