Diaby has joined Villa for a club-record price.
Saudi Arabia was interested in the winger, but he selected the Premier League instead.
Diaby has joined the team in the United States.
Al Nassr, a Saudi Arabian club, were also interested in Diaby and engaged in a bidding battle with Villa, but the 24-year-old chose to join Unai Emery at Villa Park instead.
The transaction is now final, and Diaby has already traveled to the United States to begin preseason training with his new squad.
Villa are said to have paid more than £50 million to get Diaby, who becomes the club’s new record signing.
Diaby is Villa’s third signing of the summer, joining midfielder Youri Tielemans and center-back Pau Torres.
Villa have had an expensive summer, relying on the experience of new director of football Monchi to help them acquire some high-profile targets and continue their drive for European football next season.
Diaby, a natural right winger, had his most productive season last year. The Frenchman picked up 14 goals and 11 assists in 48 games across all competitio
