John Blackadder (or Blackader) (ca. 1622–1685) was an eminent Presbyterian Covenanter preacher in Scotland during the period of the Commonwealth of England (1649–1660). Of the times MacPherson said that "after the first rejoicings of the Restoration were over, the Covenanters — Resolutioners as well as Protesters — were speedily disillusioned, and it became evident that the aim of Charles II and the junta of self-seeking noblemen who were in control of the affairs of Scotland was to establish in Scotland something approximating to an oriental despotism. The Presbyterian system, in which an Assembly of ministers and elders controlled the affairs of the Kirk, had to be supplanted by an Episcopal, with a hierarchy controlled by the Crown and easily manipulated in the interests of tyrannical rule." Despite a government ban he continued to preach in the fields. He was arrested and imprisoned in 1681 and died in jail on the Bass Rock.