As if!

“Clueless” icon Alicia Silverstone was mistaken for one of Avril Lavigne lackeys at Christian Siriano’s star-studded New York Fashion Week show at the Pierre on Friday.

Silverstone was sitting front row at the event and appeared “confused” when a guest asked her if she worked for Lavigne, according to a source, who attended the show. When she realized her faux pas, the attendee “was like, ‘Oh my God. I’m so sorry.'”

“Alicia was a good sport about it. She just kind of laughed,” the spy told Page Six.

Meanwhile, there was no mistaking Janet Jackson. The pop legend arrived to the hotel with an entourage, including her dancers, while celeb fans like Laverne Cox and Quinta Brunston were left star-struck.

We’re told Cox and Brunston fanned out over Jackson backstage. “Laverne was balling. She could not catch her breath, telling Janet how much she meant to her,” a source said.

We hear Jackson left Brunston giddy after she revealed she was a fan of her show “Abbott Elementary.” She also told Laura Linney, who was seated between Jackson and Silverstone, that she was a fan of “Ozark” because, according to our spy, “She went to high school with [the show’s leading man] Jason Bateman.”

Siriano pulled out all the stops to celebrate the 15th anniversary of his fashion line. He surprised guests with Sia, who serenaded the crowd, singing her hits “Chandelier” and “Diamonds.”June Ambrose, Elaine Welteroth, Fern Mallis, Fashion Bomb editor Claire Sulmers, Sarah Hyland, Padma Lakshmi and singer Cody Belew were a few more notables at the show.

The designer celebrated with two after parties. Jackson appeared at his first bash at The Ned in Nomad. He held an after-after party at Nolita hot spot the Mulberry, where Silverstone cut a rug.