Douglas has signed a three-year deal with Besiktas after leaving Barcelona as a free agent this summer.
The Black Eagles officially unveiled Douglas today wearing the team jersey putting pen to paper alongside sporting director Ali Naibi at the club headquarters in Akaretler, Istanbul.
Douglas will join the rest of his new teammates who are currently in Austria for pre-season training.
The 28-year-old Brazilian spent last season on loan at Sivasspor so he is no stranger to the Turkish Super Lig.
Douglas was in impressive form for Sivasspor last term scoring three times and providing seven assists in 32 appearances in the league.
Besiktas made signing a new right-back a priority as Gokhan Gonul is now 34-years-old and will need support.
With the signing of Douglas Besiktas have sufficient strength and depth in the right-back position.
The Black-Whites finished last season in 3rd place in the league and will compete in the Europa League for the 2019-20 season.