The 21-year-old, who was on loan at Hull City last season, is set to sign a five-year contract with the Magpies according to Sky Sports.
With only a medical to complete, the defensive midfielder is likely to be playing under Rafael Benitez sooner rather than later.
Able to play at either full-back, centre-back, or defensive midfield, Hayden has only ever made two appearances for the Gunners – both in the League Cup.
Coming through the north Londoners’ youth system, the versatile youngster has also played in all of England’s youth teams up to the under-20s.