Her popularity and fighting prowess have landed her in the enviable position as the featured attraction in a UFC pay-per-view main event.
This isn't a normal main event, though.
This is the debut of female fighters in the UFC, and no one has spearheaded this movement more than Rousey. Her good looks and amazing submission skills have made her a hot name outside of the MMA community.
On Saturday, she'll have to carry the event from a commercial standpoint. Hardcore MMA fans would have shelled out the requisite cash to watch the pay-per-view if Dan Henderson and Lyoto Machida were the featured bout.
Rousey's appearance is historic, and Dana White hopes his new cash machine will open up a new audience. White's not in the octagon, though. Rousey is the one who has to succeed with so much riding on her performance.
It takes two to fight, so of course Rousey has an opponent. Her name is Liz Carmouche, but the woman they call Girlrilla doesn't appear to have much of a shot against Rousey.
How will Rousey's UFC debut end?
Her record is an acceptable 7-2, but she's on a two-fight losing streak. Each woman fought Sarah Kaufmann in her last fight, but the results were strikingly different.
Rousey demolished Kaufman, defeating her by—you guessed it—an arm bar. Carmouche lost a unanimous decision to Kaufman. I'm not sure how that makes her an opponent worthy of facing Rousey in the main event, but here she is.
Carmouche has no pressure in this fight. Almost no one expects her to win, and if she loses she'll likely fade back in to obscurity. Losing won't be as inconsequential for Rousey.
If Rousey comes up short, it will harm the perceived legitimacy of her division in the UFC.
It is important for Rousey to have some sustained success before she loses. Right now, her fame is the most important aspect of establishing and putting over the women's division in the UFC. It may be unfair, but an upset on Saturday could make her debut much ado about nothing. If this were to happen, who would White push as the top female fighter?
Without that element, where is the appeal for the division? Nowhere. It doesn't exist.
This is the burden Rousey will carry on Saturday and for the foreseeable future.