Terms of the deal, which was first reported by Yahoo Sports, haven't been disclosed, though Wall is expected to re-emerge with the brand as a headlining athlete for several of its new modernized lifestyle basketball silhouettes.
After spending most of the past two seasons wearing various Nike models, Wall recently wore his Adidas JWall 1 signature shoe from 2014, along with the brand's new BYW X model, a modern take on past iconic Kobe Bryant models.
"The people that were there when i was there are not there anymore," Wall told reporters Tuesday. "It's a whole new start. ... I go to a new school, get a new principal. I might not like the old principal, but the new principal might be cool. So these guys might end up being cool.
"It is a fresh start for both of us. We're both excited, happy, and we'll see where this takes us."
The four-time NBA All-Star returns to Adidas after a hiatus that saw him leave the company in late 2015 amid stalling extension talks.
Shortly before being selected No. 1 in the 2010 NBA draft, Wall signed a five-year endorsement deal with Reebok that paid him a base salary of $2.5 million per year but could have ballooned to as high as $25 million in total through a variety of performance and sales incentives.
By January 2013, Reebok's parent company, Adidas, moved Wall over to its own growing roster of NBA players, as Reebok soon shifted away from the performance basketball category.
Just as Adidas was set to launch his second JWall signature shoe in 2015, Wall turned down an eight-year, $66 million deal from the company, according to industry sources.
With Wall wearing Nike sneakers in games the past two seasons, Adidas re-engaged Wall's representatives at the start of this season on rekindling the partnership and bringing him back into the fold.
Wall signed a four-year, $170 million extension with the Wizards this past summer that begins in 2019.