The deal includes lines of high-end sportswear and footwear. They will also launch new community centers to help members of underserved communities express creativity through art, fashion music and sports.
In a statement, Rocky recalls growing up in Harlem with limited resources to channel his creativity and hope to help kids today "go from school to a safe place to create without boundaries."
The first community centers will be in Baltimore, Los Angeles and New York.
Rocky's apparel and footwear collection will be housed by Under Armour Sportswear, the company's lifestyle product initiative.
A$AP Rocky joins other Under Armour signed celebrities including Stephen Curry, Cam Newton, Misty Copeland and Jordan Speith.