The heavyweight fight will headline UFC Fight Night in December, most likely in Las Vegas.
Lewis (25-8) is coming off an interim title loss to Ciryl Gane at UFC 265 on Aug. 27 in Houston. Prior to the loss, Lewis had won four straight, including a knockout over Curtis Blaydes at UFC Fight Night on Aug. 7.
Daukaus (12-3), of Philadelphia, is a heavyweight breakout as of late, with a UFC record of 4-0 since signing with the promotion last year. He is coming off a TKO finish over Shamil Abdurakhimov at UFC 266 last weekend in Las Vegas.
It is the first headliner opportunity for Daukaus in the UFC.