Cameronians, a sect of Scotch Presbyterian dissenters, named after Richard Cameron. James I. had enforced on his Scottish subjects a liturgy which the people abhorred. This exercise of the royal prerogative led in 1638 to the formation of the covenant, "in behalf of the true religion and freedom of the kingdom." The organization of the Scottish presbytery was still further completed in the adoption of the Presbyterian form of church government, a Calvinistic confession of faith, and the two catechisms, which documents are still the standards of the Scottish kirk. The act of 1661 of the English and Scotch parliaments against conventicles, the legalized persecutions under Turner, Dalziel, and Drummond, the famous writ of law-burrows issued by Charles II. in 1670, the intercommuning expedient of Lauderdale and Sharpe, and the execution of Mitchell in 1679, had all contributed to exasperate the Covenanters to a point where they thought forbearance ceased to be a duty. The Covenanters had made a stand at Bothwell Bridge, and had been disastrously defeated. Many of them sought to screen themselves from royal vengeance by frequenting the churches of the indulged ministers.

But a few, headed by Cameron and Cargill, met at Sanquhar, June 22, 1680, and there promulgated "A Declaration and Testimonie of the true Presbyterian, Anti-Prelatic, Anti-Erastian, and Persecuted Party in Scotland," proclaimed war against the king as a tyrant and usurper, and protested against receiving the duke of York in Scotland. Only 66 men could be mustered to sustain this declaration. They took their stand at Aird's Moss on July 20 following, where Cameron and several of his followers fell in a skirmish. Cargill escaped and continued to preach the doctrines of the sect in fields and woods. When the royalists added the test (1681), the Covenanters, or Cameroni-ans, as they were henceforth known, formally denounced it at Lanark, Jan. 12, 1682, and again affirmed the Sanquhar declaration. This they repeated in 1684, and again in 1685, on the accession of the duke of York as James II. They remained inflexible throughout the reign of that king, and supported the prince of Orange on his assuming the crown of England, but were displeased by the form in which the Presbyterian church was restored.

They subsequently exerted all their influence against the union of Scotland and England. They are in Scotland sometimes denominated "Old Presbyterian Dissenters," as Calvinistic in doctrine, Presbyterian in government, and dissenters from the church of Scotland. The presbytery of this denomination was not organized till Aug. 1, 1743, when an act of toleration was procured in their favor, under the appellation of the "Reformed Presbytery." They are now, both in Great Britain and the United States, called Reformed Presbyterians. (See Presbyterianism).