John Warner (Lord Mayor)

John Warner (died 27 October 1648) was an English merchant who was Lord Mayor of London in 1647.

Warner was a city of London merchant and a member of the Worshipful Company of Grocers. He was Sheriff of London from 1639 to 1640. On 12 March 1640, he was elected an alderman of the City of London for Queenhithe ward. From 1642 to about 1645, he was a colonel in the Green Regiment. In 1647, he was elected Lord Mayor of London.