The 135-pound bout will take place at The Palms in Las Vegas, officials confirmed.
Davis (17-6) hasn't fought since April 2015. She gave birth to a son earlier this year and is now set to resume her fighting career.
The Canadian bantamweight is 4-1 in the UFC. Her only loss came in the form of a 16-second knockout to Ronda Rousey in July 2014.
McMann (9-3) is looking for her second win of 2016, as she defeated Jessica Eye via decision in May. The former Olympic wrestler also suffered a first-round knockout loss to Rousey in 2014. She is 2-2 since that defeat.
A flyweight championship fight featuring Demetrious Johnson is scheduled to headline the TUF 24 Finale.