Minor poet. Born in Kilmarnock, Turnbull began writing poetry while employed in a carpet factory there. Later he moved to Glasgow, where he worked as a labourer. He became an acquaintance of Robert Burns (1759-96) and his Poetical Essays were published in Glasgow in 1789.
Turnbull took up acting and joined a company in Dumfries. He married an actress and the couple emigrated for the USA.