John Ker, Scottish spy (d. 1726)
John Ker (8 August 1673 – 8 July 1726), born John Crawford in Crawfurdland, Ayrshire, was a Scots Presbyterian linked with Cameronian radicals who between 1705 and 1709 acted as a government informer against the Jacobites. Dogged by financial issues most of his life, he died in King's Bench Prison in 1726.