John George Jackson was an architect active in the early- to mid-19th century.
Johnson was born in Leicester. He moved to London before his thirtieth birthday and in the late 1760s was engaged by William Berners in speculative building of Berners' estate in Marylebone. For most of the rest of his life he lived in one of the houses that he had built in Berners Street. In 1782 he succeeded William Hillyer as Surveyor to the County of Essex, a position that he held for thirty years, retiring at the age of 80. In 1785 he became a partner with Sir Herbert Mackworth and others in Dorsett and Co, a bank in Bond Street, but Mackworth left before 1792, the bank failed in 1797 and was wound up in 1803. After this, Johnson moved from Berners Street to Camden Town, and on his retirement in 1812 returned to Leicester, where he died. He was buried in St Martin's Church (now Leicester Cathedral) where he is commemorated on the base of a monument by John Bacon, originally erected in 1786 as a memorial to his parents.