Are you ready for dresses over jeans again?

Katie Holmes' recent red carpet outfit caused a stir online. Her stylist takes us behind the look.

For some, the early 2000s was a fashion fever dream. Juicy Couture tracksuits. Hoodies under blazers. Wrists cluttered with rainbow rubber bracelets. Graphic tees, vests, v-necks and thin scarves. unironic fedoras. Double denim (or all denim all, à la Britney Spears and Justin Timberlake). The list goes on.

But for those who were old enough to feel during those years, the return of some of these trends can elicit strong reactions, like a shocking visit of the ghost of your past. Now, thanks to Katie Holmes, we have a moving new entry into the ongoing Y2K style revival debate: the dress-over-jeans look.

Friday, the actress, 43, attended the iHeartRadio Jingle Ball concert in New York, walking the red carpet in a dark blue strapless Tove top (which some called a minidress), loose straight jeans and Margiela sneakers. At the concert, where Dua Lipa, Lizzo, the Backstreet Boys, Demi Lovato, the Kid Laroi and other artists performed, Ms. Holmes took the stage to introduce musician Charlie Puth. She had previously attended the Jingle Ball, including the 2017 event where she and her daughter, Suri Cruise, presented Taylor Swift's performance.

We say goodbye to trends, packing our cargo pants and dazzling baby tees – only, in some cases, to see those same trends come back with a vengeance. As predicted earlier this year, low-rise pants are back in full force, with knock-on spinoffs like the deliberately unbuttoned look.

Some Gen Zers are embracing the chaos of the most daring looks of the early 2000s, imbuing their personal style with nods to trends and even running TikTok accounts dedicated to Y2K fashion. About 20 characters in some of this year's popular movie and TV shows, like Portia in HBO's "The White Lotus," wear vintage pieces from the 90s and early 2000s.

Photos of Ms. Holmes' red carpet outfit made their way onto social media over the weekend, sparking discussions about her outfit and the dress-over-jeans trend of yesteryear. People have been sharing photos of celebrities who wore similar looks years ago, like Anne Hathaway at the 2004 "Ella Enchanted" premiere, Miley Cyrus at the 2006 Teen Choice Awards, and Ashley Tisdale during her starring days. Disney hits like "High School Musical" and "The Suite Life of Zack and Cody."

Brie Welch, Katie Holmes' personal stylist, has worked with the actress on her look for the Jingle Ball. According to Mrs. Welch, the choice was a combination of her style and Mrs. Holmes' taste and practicality. the top was stylish and would be fun paired with jeans, creating a more youthful feel to Jingle Ball and the atmosphere there,” Ms. Welch wrote in an email. (A representative for Ms. Holmes did not respond to requests for comment.)

At first glance, some people online assumed the red carpet ph...