Former Arsenal midfielder Edu has been appointed as the club's first technical director.
The 41-year-old returns to Emirates Stadium after leaving his role as general coordinator of Brazil.
The Brazilian played for Arsenal between 2001 and 2005 winning two league titles, including the 'Invincibles' season of 2003-04.
"Arsenal has always had a special place in my heart and I'm thrilled to be returning to this great club," he said.
"We have a strong squad and some very talented young players with fantastic people at every level. I'm looking forward to helping make a difference."
Arsenal say Edu will oversee the work of first-team coaches, the academy and player scouting and recruitment.
Arsenal head of football, Raul Sanllehi, added: "He has great experience and technical football knowledge and most importantly is a true Arsenal man. He understands the club and what we stand for to our millions of fans around the world.
"His arrival is the final and very important part of the jigsaw in our development of a new football infrastructure to take us forward."
Edu's appointment completes a period of significant upheaval for the club off the field.
Arsene Wenger stepped down as manager in May 2018 after 22 years in charge and was replaced by Unai Emery.
Ivan Gazidis left his role as chief executive in October to take up a similar position at AC Milan.
Sven Mislintat then stepped down as head of recruitment in February after just 14 months at the club.