The fifth in line to the British throne, who has been dating the U.S. actress since last summer, brought Markle as a guest to Jamaica for the wedding of one of his oldest friends.
Harry flew to Jamaica on a commercial flight to perform usher duties for Tom Inskip.
Harry was among 14 ushers at Inskip's wedding to Laura Hughes Young at Hopewell Baptist Church. The intimate church, with wooden pews and a wooden ceiling, also played host to Sarah Ferguson, who was a guest at the wedding.
The wedding reception took place at the exclusive Round Hill Hotel and Villas in Montego Bay, Jamaica.
Markle jetted to Jamaica from Toronto to join Harry as his guest. The actress wore a $1,500 floral dress by Erdem and was seen cuddling and clutching Harry with her arm around his back.
Harry and Meghan are reportedly holed up in one of the hotel's super posh, ocean view villas, which can cost as much as $2,000 a night. The villas boast private pools and terraces overlooking the Caribbean.
The couple previously vacationed in Norway to view the Northern lights after Christmas and have been photographed holding hands after date nights in London at Soho House and a play in the West End.
That Markle, who married her first husband in Jamaica in 2011, and Harry are now socializing in public at an event with Harry's friends is significant.
Inskip, known as "Skippy," attended Eton College with Harry and his father is a friend of Prince Charles. Inskip, who was by Harry's side after the death of Harry's mother, Princess Diana, is often referred to as Harry's "wingman." Inskip was also with Harry in Las Vegas in 2012 on a trip from which naked pictures of Harry later surfaced.
Harry and Markle have been spending more time together while Markle is on a hiatus from her filming commitments. They spent nearly all of last month together at Prince Harry's Nottingham Cottage at Kensington Palace and speculation is mounting over if and when Harry will propose to Markle.
Harry will be spending more time later this year in Toronto, where Markle films her TV show, "Suits." The third Invictus Games, which Harry founded, will be held in Toronto in late-September.