Brazilian Vieira (12-2) started her professional MMA career with a 10-fight win streak before going 2-2 in her last four outings, though a victory over Miesha Tate in November ensures she enters this bantamweight meeting with Holm with momentum behind her.
Meanwhile, Holm (14-5) is looking to move a step closer to regaining the title at 135lbs, having famously taken it from Ronda Rousey with a head-kick knockout in 2015. Holm, 40, dropped the gold to Tate in 2016 and failed to win it back against Amanda Nunes in 2019, and the American has also twice come up short in pursuit of the UFC women’s featherweight strap.
In contrast, Vieira is seeking her first title shot in the promotion, and a win against Holm would go a long way to helping the 30-year-old achieve that goal.
Here’s all you need to know.
When is it?
The event will take place on Saturday 21 May at the UFC Apex institute in Las Vegas.
The prelims will begin at 9pm BST (1pm PT, 3pm CT, 4pm ET), with the main card following at 12am BST (4pm PT, 6pm CT, 7pm ET) on Sunday morning.
How can I watch it?
The card will air live on BT Sport in the UK, with the broadcaster’s app and website also streaming the fights.
In the US, ESPN+ will stream the action live, as will the UFC’s Fight Pass.
Holly Holm vs Ketlen Vieira (women’s bantamweight)
Santiago Ponzinibbio vs Michel Pereira (welterweight)
Chidi Njokuani vs Dusko Todorovic (middleweight)
Jailton Almeida vs Parker Porter (heavyweight)
Eryk Anders vs Jun Yong Park (middleweight)
Joseph Holmes vs Alen Amedovski (middleweight)
Polyana Viana vs Tabatha Ricci (women’s strawweight)
Omar Antonio Morales Ferrer vs Uros Medic (lightweight)
Jonathan Martinez vs Vince Morales (bantamweight)
Chase Hooper vs Felipe Colares (featherweight)
Elise Reed vs Sam Hughes (women’s strawweight)