Kick off your heels, ladies.

23-time Grand Slam winner Serena Williams showed up to the royal wedding of Prince Harry and Meghan Markle on Saturday in a pink Versace dress with matching heels — but she swapped the pumps out for a pair of black and white Valentino sneakers for the black-tie reception, hiding them under her full, floral Valentino ball gown with fitted black bodice.

She tipped her Instagram followers off, however, by flashing a peek at the couture kicks in a short video clip. “Little known fact: I often wear sneakers under my evening gown,” she wrote, adding, “I tend to be comfy for long nights #beingserena.”

She’s not the only one saying “heel no!” Actress Kristen Stewart ditched her sky-high Louboutins at the Cannes Film Festival last week to climb the stairs before the premiere of Spike Lee’s “BlacKkKlansman.”

This was possibly in defiance of the controversial dress code that says women must wear high heels on the French red carpet, which stems from a 2015 Cannes screening of “Carol,” when a group of women were reportedly denied entry for wearing flat shoes.

Kristen Stewart took off her heels at the Cannes Film Festival red carpet. (Photo by Andreas Rentz/Getty Images)

At that time, Stewart told reporters, “If (a man and I) were walking the red carpet together and someone stopped me and said, ‘Excuse me, young lady, you’re not wearing heels. You cannot come in.’ Then (I’m going to say), ‘Neither is my friend. Does he have to wear heels?’ It can work both ways.” Other actresses like Susan Sarandon and Emily Blunt have also worn flats in previous years despite the fashion rule.

L-R Susan Sarandon, Geena Davis and Ramin Setoodeh attend Kering Talks Women In Motion At The 69th Cannes Film Festival on May 15, 2016. (Getty images).

But even off the red carpet, women in high positions agree that climbing the corporate ladder doesn’t have to be done in heels. Fashion journalist Hannah Rochell rocked heels early in her career — but now at 41, she’s decided to only wear flats for one obvious reason: heels hurt.

“I had never really liked the aesthetic of heels,” admits Rochell, who grew up wearing retro sneakers. “But when I started working in fashion, I felt a certain pressure to wear them like everyone else was. After completely losing my style mojo, falling over a lot and crying from pain at train stations, I’d had enough. One day I just woke up and decided never to wear heels again.”

Rochell, who lives in a pair of all-white Lacoste trainers, turned her no-heels movement into the EnBrogue.com blog, which pairs fancy flats with women’s workwear. She says it’s also a feminist fashion statement. “Women are just fed up with being uncomfortable, and of conforming to what is traditionally a male-perspective of ‘acceptable’ dressing — whether that’s at work, at weddings or on the red carpet,” she said.

SEE ALSO: High heels are the only shoe emoji for women. This controversial ballet flat could change that

And the pain is real. The American Osteopathic society has said heels put the foot at an angle that pulls muscles and joints out of alignment — so the effects aren’t just limited to the feet. Women who wear high heels for extended periods of time tend to have lower back, neck and shoulder pain, because the shoes disrupt the natural form of the body.

It’s worth noting that these weren’t always just a female torture device. High-heeled shoes were originally worn by men, in fact, dating back to the 10th century. Gents from horseback-riding cultures wore heels on their shoes to help stay in the stirrups. The Persian royalty wore inch-high heels, and the elevated trend spread to European monarchs such as Louis XIV — and women eventually stepped into the heightened fashion, as well.

Now many women are slipping back in to something more comfortable and practical — but without sacrificing style.

“I wear flats with everything from dresses to capri dress pants to wide leg trousers,” Ashley Breault, 26, a district sales manager at General Motors, tells Moneyish. Her favorites are a pair of $50 Toms lace slip-ons with sparkles that she says are a perfect fit for her business meetings on the road, like her last one in Vermont.

“A big part of my job is building relationships with the decision-makers at dealerships. The shoes were a great conversation starter, which helped me break down some walls and get to know the owner at a more personal level to see what drives her and how she runs her business,” she says.

Adam Tucker, founder of the women’s shoe brand Me Too, started his business primarily selling affordable ballet flats and comfortable slip-ons to women in the ’90’s, when they still primarily opted for heels over flats in the office. But now he’s noticed a major shift in demand for flats and sneakers for work.

SEE ALSO: How the 22-year-old shoe brand Me Too is finding its soul through #MeToo

“The fashion world is becoming more casual — with an edge,” he says. “Women are not feeling like they need to be dressed a certain way to be seen and to be heard.” And his brand is meeting that demand with a new line of dressy sneakers this June.

Chic sneaks have become a shoe-in for flats and heels in the recent athleisure-obsessed years. The sneaker industry generated a whopping $19.6 billion in sales last year, according to global information company The NPD Group. What’s more, sales of high heels dropped 12% in the past year, while women’s sneakers jumped 37%.

Even Vogue urged women to “ignore those impossibly high heels” in favor dress pants and sneakers in a 2015 editorial featuring Kate Moss in silver trousers styled with black Adidas. In a similar fashion, Phoebe Philo, the former creative director of Celine, has practically made the dress pants-and-sneakers combo her professional uniform. DKNY’s 2015 Spring/Summer runway collection featured models sporting formal dresses and pleated pencil skirts paired with flatform sneakers.

Now, 2018 is shaping up to be the year of the “ugly sneaker” trend, with the likes of Kim Kardashian West, Kendall Jenner and Hailey Baldwin pairing business casual blazers with clunky, so-called “dad sneakers” that you can find for $50 at Footlocker or for up to $895 by Balenciaga. https://nypost.com/2017/12/04/the-fashion-world-is-obsessed-with-dorky-dad-shoes/

Just ask Alexandra Machover, 27, who solely wears sneakers to work and during evenings out.

“I’m currently wearing all-white Reeboks with a flowy dress,” says Machover, a Brooklyn-based video producer. “I honestly wear sneakers with every outfit now: dresses, jeans and a vintage tee, track pants and a crop top. They always look amazing.”

When it comes to dressing for the boardroom, some women still have an affinity for high heels, because they say it makes them feel empowered.

“Heels give me an instant confidence boost,” says Alex Taylor, the vice president at Marina Maher Communications in Manhattan. “I feel better when wearing heels — and when I feel my best, I perform my best.”

When it comes to pairing the right flat with workwear, designer Dennis Basso (who has dressed Naomi Campbell and Anna Wintour) says cropped dress pants and a pointy flat or leather loafer (he praises Gucci) can work wonders.

“A great-looking slide with a pantsuit looks fantastic,” he adds. “If you’re going flat, whether it’s a pointy toe flat shoe or a ballerina, a narrow pant with an ankle slit or cropped pant is always a good look.”

This article was originally published on May 15, 2018 and has been updated with Serena Williams.