John Abernethy (c.1570–1639) was a Scottish clergyman who served as Protestant Bishop of Caithness.
He was one of the first group of students at the University of Edinburgh under Principal Robert Rollock and graduated MA in 1587.
Despite this, in December 1616, through the influence of James Law, Archbishop of Glasgow, he was appointed Bishop of Caithness.
This title was largely nominal, and he continued his parochial duties in Jedburgh.
This promotion was preceded by the award of Doctor of Divinity from the University of Edinburgh and appointment to the Court of the High Commission.