The bout represents the first time women will compete in the UFC, and it comes a little over a year after UFC President Dana White told TMZ that women would never appear in his promotion.
Apparently money talks, and like most promoters, White listened.
If you're interested in catching the action, there are various ways to be a part of UFC 157. Here are the specifics on the event, and a few things you should know about the fighters in the main event.
When: Saturday, 10 p.m. ET
Where: Honda Center, Anaheim, Calif.
TV: Preliminaries on FX, Main Card on Pay-Per-View (details on ordering the event can be found here)
Live Stream: Preliminaries streamed on Facebook, and entire event is available to order for online viewing.
Sports Bars: The event will be shown at selected bars across the United States. Click here to see locations near you.
Other Fights on the Card
Light Heavyweights - Dan Henderson vs. Lyoto Machida
Featherweights - Urijah Faber vs. Ivan Menjivar
Heavyweights - Lavar Johnson vs. Brendan Schaub
Welterweights - Neil Magny vs. Jon Manley
Middleweights - Court McGee vs. Josh Neer
Lightweights - Michael Chiesa vs. Anton Kuivanen
Welterweights - Josh Koscheck vs. Robbie Lawler
Featherweights - Dennis Bermudez vs. Matt Grice
Lightweights - Caros Fodor vs. Sam Stout
Welterweights - Brock Jardine vs. Kenny Robertson
Welterweights - Nah-Shon Burrell vs. Yuri Villefort
Rousey's Path to UFC 157
Though others such as Gina Carano and Cristiane "Cyborg" Santos have come before her, Rousey is the first mega-star in women's MMA.
She has appeared in the ESPN the Body Issue, she has almost 190,000 followers on Twitter, and she's not just appearing in a UFC event; she's the featured attraction.
This is one of the fastest rising stars in all of sports.
Rousey's combat base is judo. She won a bronze medal in the event at the 2008 Olympic Games in Beijing. She used that as a springboard to a successful career in the Strikeforce MMA promotion.
It was there she became famous for her good looks and signature armbar. Rousey has used this technique to win all six of her fights, and she is a perfect 6-0 professionally.
She's a cash machine, and Dana White wants a piece of the pie.
Carmouche's Path to UFC 157
This former Marine and veteran of the Iraq war has compiled a 7-2 record professionally. She has lost her last two bouts, and thus this handpicked opponent is not expected to give Rousey much trouble.
In fact, both Carmouche and Rousey battled Sarah Kaufman in their last bout. Rousey decimated Kaufman with the armbar, but Carmouche lost to Kaufman by unanimous decision.
The woman they call "Girl-Rilla" will be trying to pull the monumental upset and ruin Rousey's coming-out party.