Rachel McAdams Makes Surprise Saturday Night Live Cameo Introducing Reneé Rapp as Musical Guest

Reneé Rapp had a surprise guest introducing her Saturday Night Live performance — the original Mean Girls' Regina George!

Rachel McAdams, who played the role in the 2004 hit movie, made an unexpected cameo on the show to introduce Rapp, 24, who stars as Regina George in this year's musical remake of the iconic film.

Appearing on stage in a red pant suit by Generation Love and purple roll-necked sweater, McAdams, 45, — who starred alongside the likes of Lindsay Lohan, Amanda Seyfried, Lacey Chabert in the original movie — clasped her hands together and grinned as the delighted audience cheered at her surprise presence on the SNL stage.

"Ladies and gentlemen, once again, Reneé Rapp!" she said before gesturing over to Rapp, who then began her performance of "Not My Fault" with Megan Thee Stallion, who joined her on stage for the song in another exciting surprise cameo.

Rapp impressed with her vocals as the musical guest on this week’s episode of SNL, hosted by Jacob Elordi, performing both "Not My Fault" and her track "Snow Angel," which was introduced by Elordi.

Meanwhile, McAdams also appeared in a sketch where she played an actress called Natalie Partman who had started an OnlyFans and had been sued by the real Rachel McAdams, asking Elordi, 26, for career advice for "someone who looks like a famous person."

In a fun moment following the show, rapper Megan — who in "Not My Fault" raps that she is the "Black Regina George" — shared a post on Instagram of herself, McAdams and Rapp recreating the famous Spiderman pointing meme.

"Cause huhhh 🥹 all the Reginas in one room 🤭💖 #snl" she captioned the post.

In the first photo, Megan and the two actresses stood on the SNL stage in a triangle with their arms outstretched, pointing to one another. As the rapper made a shocked face, McAdams pouted and Rapp smiled at the camera.

The second slide in Megan's post featured the Spiderman meme itself, featured three versions of the superhero in the same pose.

Ahead of the show, a Thursday promo video teased the singer's appearance. During the fun clip, which featured Elordi and cast member Bowen Yang, Rapp called the Priscilla actor "so babygirl."

"I'm a babygirl? So what's Reneé?" Elordi then asked.

"Me?" Rapp answered with a smile. "Oh, I'm mother."

On Dec. 16, the comedy sketch show announced that Elordi, 26, and “Poison Poison” singer would make their debuts as host and musical guest, respectively. Rapp reposted the graphic on Instagram with the caption, “yeah you’ve got to be f---ing kidding me.”

Stars like Rachel Zegler, Ariana DeBose and Rapp’s Mean Girls mom Busy Philipps showed their enthusiasm and support in the comments.

The surprise introduction on Saturday comes after, in an exclusive chat with PEOPLE earlier this month, Rapp had heaped praise onto her character, originally played by McAdams in the 2004 film.

“She’s determined. Something about that is hot to me,” The Sex Lives of College Girls actress said. “The mean girl is always hot to me.”

Rapp has had a busy start to the year following a packed 2023.

Last year began with her filming the Tina Fey-written movie musical Mean Girls. At the same time, she recorded her debut studio album Snow Angel, which was released in August. The album was accompanied by the Snow Hard Feelings Tour, which began in September and continues into 2024. 

Rapp is reprising her Broadway role of Regina George in her role in the 2024 film adaptation of the stageplay. The movie also costars with the likes of Fey, Philipps and Christopher Briney.

Saturday Night Live airs Saturdays at 11:30 p.m. ET on NBC.