John Alleyn or Allen (1 March 1621 - 26 June 1663) was a Cornish politician.
John Alleyn was the son of Giles Allen, Rector of Little Waltham and his wife Elizabeth, daughter of William Massam. John was educated at Emmanuel College, Cambridge, where he matriculated in 1629, before being admitted to Gray's Inn in 1642.
He was returned MP for St Michael, Cornwall in 1660.[1] He was elected a Fellow of the Royal Society in May, 1663 just before his death in Little Waltham, Essex. [2]