Sir John Floyer (3 March 1649 – 1 February 1734) was an English physician and author.

He was the third child and second son of Elizabeth Babington and Richard Floyer, of Hints Hall, a since demolished country house.

He practised in Lichfield, and it was by his advice that Dr Johnson, when a child, was taken by his mother to be touched by Queen Anne for the king's evil on 30 March 1714.

As a physician, Floyer was best known for introducing the practice of pulse rate measurement, and creating a special watch for this purpose.

He was an advocate of cold bathing, and gave an early account of the pathological changes in the lungs associated with emphysema.