He was born the son of Deane Swift of Dublin, (who was a cousin of Dr. Jonathan Swift) and educated at St Mary Hall, Oxford, graduating B.A.
He studied law at the Middle Temple and was called to the bar in 1774.
After practising law for a few years, he moved to live in Dublin after inheriting some property in Limerick after the death of his father in 1783.
In another pamphlet entitled Animadversions on the Fellows of Trinity College, Dublin he accused some of the fellows at Trinity with having broken the rule which prohibited them from marrying, earning him a twelve months' prison sentence in the Marshalsea prison for libel.
In 1800 he was awarded the Cunningham Medal by the Royal Irish Academy for his essay on The origin and progress of rhyme.