William Gillespie was the eldest son of John Gillespie, minister of Kells. He studied at the parish school before entering the Unversity of Edinbugh (1792) where he studied theology and medicine. In 1800 Gillespie was ordained as assistant minister to his father, whom he succeeded at Kells in 1806. In 1820 he was caught up in the controversy surrounding Queen Caroline, and arrested for including "Bless also the Queen" in a sermon. He married in 1825, only to contract a disease on his marriage tour which proved fatal shortly afterwards. Gillespie contributed to the Scots Magazine and other periodicals.
The progress of refinement an allegorical poem, with other poems. 1805.
Consolation with other poems. 1815.
The rebellion of Absolom: a discourse. 1820.