Playing a tough, trousers-wearing NYPD sergeant makes “Law & Order: SVU” star Mariska Hargitay appreciate the glamour at Fashion Week — even if her hectic filming schedule allows only one show.

“I’m busting perps all day, so I love the moments where you get to be ladylike,” Hargitay tells The Post at her pal Lela Rose’s show on Tuesday, adding that she would love to get to wear one of Rose’s dresses on the show. “We sprinkle it in every couple of years that I get to wear a dress,” adds the 51-year-old.

Hargitay, who plays Olivia Benson and adopted a baby on the show this season, also dropped a hint about an upcoming plot point surrounding the tot.

“There’s a huge thing coming up about baby Noah,” she says. “It’s scary.”