Sir John Glynne, 6th Baronet (1713 – 1 July 1777) was a Welsh politician and landowner. Glynne was the third son of Sir Stephen Glynne, 3rd Baronet, and succeeded to the baronetcy after the successive deaths of his father and elder brothers in 1729 and 1730. In November of the latter year, he matriculated from The Queen's College, Oxford. Sir John stood as Member of Parliament for Flint in 1734, but was defeated after spending £35,000 on the election. However, in 1741, he was elected MP for Flintshire, which he represented until 1747.