The Gunners are expected to complete the signing of the France international, as talks with Barcelona over the acquisition of Alexis Sanchez progress
The Gunners agreed a fee with the Magpies and are set to make Debuchy their first signing of the summer as they look to replace Bacary Sagna.
The 28-year-old revealed he was in talks to join the north London club in the wake of France’s exit from the World Cup last Friday.
The terms of the deal were finalised over the weekend, allowing Debuchy to then complete a medical on Monday evening and the deal is expected to be confirmed in the coming days after formalities are completed.
Arsenal will pay €10m up front, but the fee will rise due to appearance-related add-ons.
The club's spending on transfer fees could reach the €50m mark in the next week as they are also on the verge of capturing Alexis Sanchez after agreeing a €40m fee for the Chile star with Barcelona.
Arsene Wenger moved for Debuchy after deciding to buy a proven right-back rather than a more inexperienced player in the mould of the 21-year-old Toulouse defender Serge Aurier, who had been closely pursued by the Premier League giants after it became clear that Sagna was joining Manchester City.
Having watched Juanfran, another target, sign a contract extension with Atletico Madrid, Wenger sanctioned a swoop for Debuchy.
The Frenchman has been the regular right-back at Newcastle since joining from Lille in January 2013 and started four of France’s five World Cup matches ahead of Sagna.