The smitten royal popped the question to the Suits star a year after the pair publicly announced they were dating.
Last night, an engagement appeared to be on the cards after bookies suddenly suspended betting on another royal wedding.
Rumours have been rife ever since Meghan, 36, was said to have pulled out of Thanksgiving celebrations in Los Angeles to be in London.
The divorcee travelled to the UK lastSaturday after a small leaving party in her native Canada and was seen shopping in the capital earlier this week.
She was also believed to have moved her beloved pet dogs - Labrador shepherd cross Bogart and beagle Guy - to Britain.
Meghan has been rumoured to be quitting her TV role to move to the UK ever since she was pictured canoodling with Harry, 33, at the Invictus Games in Canada in September.
The loved-up pair first met last year after being introduced by mutual pals but only announced they were together in November.
They were then spotted hand-in-hand for the first time while out on a date in London.
At the time, pals said actress Meghan had “virtually moved in” to Harry’s cottage at Kensington Palace with the couple having been “inseparable” for weeks.
On May 6 Meghan made her first public appearance as a royal girlfriend when she proudly watched Prince Harry playing polo in Berkshire.
Then in September, the pair were pictured together in Toronto as they attended the Invictus Games with Meghan's mum Doria.
Speculation was fuelled further in October when it was reported Harry had taken Meghan to Buckingham Palace for a meal with the Queen.
Now the pair are engaged, Meghan will be given a royal title by Her Majesty but would not be addressed as Princess Meghan.
To have princess as a title before your first name is an honour reserved for women who are born into the Royal Family - such as Princess Charlotte.
Instead, the actress would be known as HRH Princess Henry of Wales.
Harry will probably be bestowed a Dukedom when he ties the knot, with experts believing the couple would become the Duke and Duchess of Sussex.
Meghan was born and raised in California but now lives in Toronto, Canada, where Suits is filmed.
She opened up about her romance with Harry in an interview with Vanity Fair where she said her relationship with the Prince was a "great love story".
Actress Meghan's biggest role has been in the US TV show Suits, where she plays Rachel Zane.
But like her fiance, she is committed to charity work and is the Global Ambassador for World Vision Canada and has been to Rwanda to promote the organisation's Clean Water Campaign.
In 2011, she married Trevor Engelson, who owns a production company, but the pair split in 2013.