In 1724 he was presented by Archbishop William Wake to the rectory of Buxted in Sussex, and in September 1727 was made prebendary of Hova Villa in Chichester Cathedral, and in 1738 canon residentiary.
[1] In June 1770 Clarke was installed chancellor of Chichester (also holding the rectories of Chiddingly and Pevensey).
In August of the same year he was presented to the vicarage of Amport, the vicarial residence, which he resigned to a friend who died in July 1771.
He also wrote the Latin preface (1730) to the collection of the Welsh laws of William Wotton, his father-in-law; a translation of Joseph Trapp's Lectures on Poetry, annotations on the Greek Testament (the two latter with William Bowyer), and some notes to the English version of Jean-Philippe-René de La Bléterie's Life of the Emperor Julian.
[1] Clarke drew up a manuscript The Antiquities of the Cathedral of Chichester,’ which was presented by his grandson to Alexander Hay, the local historian.