The main card is on ESPN, starting at 10:30 p.m. ET, and the prelims are on ESPN+ at 7:30 p.m.
Holm (13-5, 6-5 in the UFC) has lost five of her last eight fights, but each of those defeats came at the hands of someone who has owned a UFC championship belt: Amanda Nunes, Cris Cyborg, Germaine de Randamie, Valentina Shevchenko and Miesha Tate. Prior to that run, however, Holm scored the biggest victory in women's MMA history, knocking out Ronda Rousey in 2015 to become bantamweight champ.
Aldana (12-5, 5-3 UFC) has won two in a row and five of six after starting her UFC tenure 0-2. She is No. 5 in the ESPN women';s bantamweight rankings, with Holm at No. 6.
The card also features another meeting of female 135-pounders: No. 2 de Randamie faces fourth-ranked Julianna Peña.
How to watch the fights:
Watch the prelims on ESPN+. If you don't have ESPN+, get it here.
There's also FightCenter, which offers live updates for every UFC card.
Saturday's fight schedule
ESPN/ESPN Deportes/ESPN+, 10:30 p.m. ET
Holly Holm vs. Irene Aldana | Women's bantamweight
Yorgan De Castro vs. Carlos Felipe | Heavyweight
Germaine de Randamie vs. Julianna Pena Peña | Women's bantamweight
Tom Breese vs. KB Bhullar | Middleweight
Dequan Townsend vs. Dusko Todorovic | Middleweight
ESPN+, 7:30 p.m. ET
Kyler Phillips vs. Cameron Else | Men's bantamweight
Carlos Condit vs. Court McGee | Welterweight
Charles Jourdain vs. Josh Culibao | Men's featherweight
Jordan Williams vs. Nassourdine Imavov | Middleweight
Loma Lookboonmee vs. Jinh Yu Frey | Strawweight
Casey Kenney vs. Alateng Heili | Men's bantamweight
Jessin Ayari vs. Luigi Vendramini | Lightweight