Evans (19-3-1) made the announcement to Fox Sports on Friday. The pay-per-view event will take place at The Mandalay Bay Events Center in Las Vegas.
A two-fight win streak has elevated Evans, 34, back into title contention. After suffering back-to-back losses in 2012, including a lopsided decision to Jon Jones in an April title bid, Evans has rebounded with wins against Dan Henderson and Chael Sonnen.
Cormier (13-0) will make his much-anticipated move to the 205-pound division. He is the No. 4-ranked heavyweight in the world by ESPN.com, but a close friendship with current UFC champion Cain Velasquez has prompted him to drop divisions.
A member of the 2008 U.S. Olympic wrestling team, Cormier has recorded decision wins against Frank Mir and Roy Nelson since joining the UFC early this year. The 34-year-old recently signed a new deal with the fight promotion.