Sir John Salusbury (1567 – 24 July 1612) was a Welsh knight, politician and poet of the Elizabethan era. He is notable for his opposition to the faction of Robert Devereux, 2nd Earl of Essex and for his patronage of complex acrostic and allegorical poetry that anticipated the Metaphysical movement.
Salusbury was a member of the Salusbury family of Lleweni in the Vale of Clywd, Denbighshire, where they owned a considerable estate, including Lleweni Hall. Various members of the family acquired honours and appointments through their support of the Tudor monarchs. He was the son of Sir John Salusbury and Katheryn of Berain, and the younger brother of Thomas Salusbury, who was executed in 1586 for his involvement in the Babington Plot against Elizabeth I.
He was born in 1567 and educated at Jesus College, Oxford, where he matriculated in 1581 aged 14. After his brother's execution, he succeeded to the estates, but the family's lands were severely reduced due to the loss of crown leases. It took him several years to restore them. He studied law at the Middle Temple from March 1595. Elizabeth appointed him as squire of the body in the same year. Salusbury became noted for his "ostentatious loyalty" to the queen, in contrast to other members of his family, who were associated with Catholic sympathies and plots against her. Salusbury was a staunch Protestant, writing to the queen's minister, Robert Cecil denouncing recusants. He was also an opponent of the Earl of Essex, with whose supporters he came into conflict in local politics. He almost killed his cousin Owen, an Essex supporter, in a sword fight in 1593. Owen was already being treated with suspicion as a potential rebel, so the duel did Salusbury no harm. The 5th Earl of Derby, his wife's brother, wrote to congratulate him for beating "that bad fellow of your name", saying that the event would be to the "advancement of your credit".