Fitzgerald was the son of Colonel John Austen (or Anster) Fitzgerald of the Dutch service and Henrietta Martin, daughter of an Antigua planter and sister of Samuel Martin MP.
Educated at Greenwich, the Royal College of Navarre in the University of Paris and the Inner Temple where his tutor was Vicary Gibbs[1] he married very late in life to Maria Howorth in December 1826.
Employed until about 1805 in the Navy pay-office Fitzgerald became subject to 'an asthma' for the last 30 years of his life and suffered from dropsy.
Lord Byron mentioned him in the opening line of his English Bards and Scotch Reviewers: Byron was mocking Fitzgerald's practice of reciting one of his poems each year, at the annual dinner of the Literary Fund, held at the Freemasons' Tavern.
Fitzgerald replied to Byron, though not publicly; in a copy of English Bards he wrote: This copy of the poem somehow came into Byron's possession, and he added a verse reply of his own, dismissing Fitzgerald as a "scribbler.