The two will replace Gwen Stefani and Pharrell Williams, said The Hollywood Reporter.
The singing divas will join returning stars Adam Levine and Blake Shelton, who have been with the series since its inception.
While Keys, 35, has previously served as a mentor for Williams' group of singers during his season-seven debut, Cyrus, 23, will make her Voice debut on season 10, during which she will serve as a key advisor mentoring all four groups of contestants. This will be the first season with two female coaches.
The 11th season of "The Voice" will air in September.
