The sportswoman took to Instagram to post a photo of the Duchess of Sussex in the £110 ‘Boss’ jacket, which makes up part of Serena’s eponymous clothing brand.
Meghan, 37, opted to wear the plaid blazer on day two of the royal tour, teaming it with a white shirt from Maison Kitsune, J Crew ankle boots and a pair of jeans from Aussie label Outlander Denim.
The royal finished the look with a slick ponytail and delicate, gold jewellery.
Serena is also using a photo of Meghan in the jacket on her website – which likely went some way in ensuring the product sold out almost instantly.
Serena launched her brand, which is aimed at ‘all the ladies out there being awesome’, earlier this year.
Other designs include a ‘Royal Duchess’ hoodie and a ‘Royal Duchess’ tee, which are thought to have been inspired by the tennis pro’s close friendship with Meghan.
The pair have been friends for years. It’s thought they met at a Super Bowl party in 2010 and, according to Meghan, “hit it off immediately”.
In addition to attending the Duchess’ May wedding, Serena was photographed at a polo match with her this summer and Meghan support Serena at Wimbledon in July.
“We’ve always had a wonderful friendship,” Serena previously said. “Every year, for a couple of years, she comes out to Wimbledon and has supported me.”
No doubt Serena will be able to help support Meghan through her pregnancy, as Serena became a mum herself last year.
She and husband, Reddit founder Alexis Ohania, welcomed a daughter named Olympia in August 2017.