Multiple sources confirmed the heavyweight bout will serve as the main event for UFC Fight Night on July 23 at O2 Arena in London. The pairing was first reported by MMA Fighting.
Aspinall (12-2) has surged into title contention behind five consecutive finishes in the UFC. His most recent came in March with a first-round submission against Alexander Volkov in London. That event marked Aspinall's first appearance as a headliner.
Four of his five UFC finishes have ended in the first round.
Blaydes (16-3) is riding a two-fight win streak, including a second-round TKO over Chris Daukaus in the main event of a UFC Fight Night on March 26. Fighting out of Colorado, Blaydes has compiled an 11-3 record in the UFC. His only losses have come against current champion Francis Ngannou (twice) and Derrick Lewis.
Blaydes and Aspinall are ranked as the UFC's Nos. 4 and 6 heavyweights, respectively.