Wenger named FIFA's development chief
FIFA said the former Arsenal and Monaco coach would be responsible for the growth of the game "for both men and women around the world", and would also be the "leading authority on technical matters", including potential changes to the sport's laws.
It added that Wenger, 70, would also be tasked with coach education and aiding a programme designed to help former players enter management.
"I very much look forward to taking on this extremely important challenge," Wenger said in a statement.
"Not only because I have always been interested in analysing football from a broader perspective but also because FIFA's mission as world football's governing body is truly global."
Rumours of Wenger making a shock return to coaching had intensified over the weekend after Wenger denied claims by Bayern Munich that they had turned down his offer to take over at the German champions after the sacking of Niko Kovac.
Bayern chairman Karl-Heinz Rummenigge then said there had been a "misunderstanding" and that the Bundesliga giants would speak to Wenger "in the near future".
However it is the new FIFA role that brings the Frenchman back to the game for the first time since 2018, when he left Arsenal after 22 years in charge.
Wenger made the Gunners one of the strongest sides in Europe, winning three Premier League titles and seven FA Cups and taking his team to the 2006 Champions League final.
He also won the French league in 1987 with Monaco, adding the French Cup four years later before departing for Japan in 1995.
"I am delighted to welcome him to the team. Since I arrived at FIFA, we have placed football at the centre of our mission, striving to learn from those who know the sport inside out," said FIFA president Gianni Infantino.
"Arsene is someone who, with his strategic vision, competence and hard work, has dedicated his life to football."
Bringing in famous faces has been a key part of Infantino's tenure at the head of FIFA. Wenger arrives following the departures of technical chief Marco van Basten last year and former deputy secretary-general Zvonimir Boban, who became AC Milan's "chief football officer" in June.