The 2021 Extreme Rules was the 13th annual Extreme Rules professional wrestling pay-per-view (PPV) and livestreaming event produced by WWE. It was held for wrestlers from the promotion's Raw and SmackDown brand divisions. The event took place on September 26, 2021, at the Nationwide Arena in Columbus, Ohio, and was the first Extreme Rules to livestream on Peacock. It was also the first and so far only Extreme Rules event to be held in September, replacing Clash of Champions that was previously held during that month; Extreme Rules was moved to October the following year.

Rebecca Mary Quin is an Irish–American professional wrestler. She is signed to WWE under the ring name Becky Lynch, where she performs on the Raw brand and is the current Women's World Champion in her fifth reign, and seven-time world champion overall. Lynch is one of WWE's most recognizable and highest-paid wrestlers. Twitter named her sixth on their list of Top Female Athletes Worldwide in 2019.