26 Bold Kate Middleton Outfits That Probably Weren't Queen Approved

Kate wore a simple red knit with skinny jeans and trainers to visit the Salthill GAA club during her visit to Ireland.

Kate dressed in holiday colors and winter boots, plus a pair of thick hunter-green socks that she rolled over her jeans, to visit Peterley Manor Farm in December.

The duchess wore wide-legged pants with a white button-down and white Sugerga sneakers to visit the garden she helped design at the Chelsea Flower Show.

Kate Middleton wore a $50 J.Crew sweater while visiting the Scout Association's UK headquarters in Gilwell Park.

After arriving in Belfast, the duchess switched into a comfortable look to play soccer with some kids. She sported a Polo Ralph Lauren cable-knit sweater pairing it with blue skinny jeans and sneakers from Sweaty Betty x New Balance.

Kate slipped into trusty jeans and sneakers at the America's Cup World Series.

During a May 2016 royal engagement with competitive sailor Ben Ainslie, Kate Middleton stepped out in skinny jeans and Adidas sneakers.

It was ski gear for both Kate and Prince William during March 2016 in the French Alps.

Kate Middleton rocked a baseball cap while boating in New Zealand in April 2014.

It was blue jeans — and wedge heels — for Kate Middleton during an October 2013 engagement in London.

Kate Middleton showed her ease in sneakers and skinnies during a June 2012 engagement.

Kate made a rare appearance in a sweatshirt while in London during December 2014.

Prince William gave a wind-jacket-clad Kate Middleton a hug during their Canadian tour in July 2011.

Far from being casual, Kate Middleton showed off her new sexy style wearing Jenny Packham at a London engagement in October 2014.

It was dark denim for Kate during a July 2014 engagement in Scotland.

Kate was snapped wearing a white bikini while vacationing in Ibiza in 2006.

Kate Middleton's 20-something party style was on display back in September 2008 in London.

It was rain boots and jeans for a June 2012 day of polo for Kate Middleton and her dog Lupo in Tetbury, England.

Call her cowgirl Kate; both Kate Middleton and Prince William dressed in cowboy hats and jeans to visit the Calgary Stampede in July 2011.

Kate Middleton wore a bright print dress during a September 2012 visit to the Soloman Islands.

Kate's country style was evident during an August 2005 visit to England's Gatcombe Horse Trials.

Kate Middleton fully embraced the low-cut denim styles of the early 2000s with out outfit she wore in June 2005 in St. Andrews, Scotland.

Kate Middleton wore a low-cut dress during a night out in July 2007 in London.