A statement from Clarence House said: “His Royal Highness The Prince of Wales is delighted to announce the engagement of Prince Harry to Ms Meghan Markle.
“The wedding will take place in Spring 2018. Further details about the wedding day will be announced in due course.
“His Royal Highness and Ms Markle became engaged in London earlier this month. Prince Harry has informed Her Majesty The Queen and other close members of his family. Prince Harry has also sought and received the blessing of Ms Markle’s parents.
“The couple will live in Nottingham Cotage at Kensington Palace.”
Fifth in line to the throne Harry, 33, has been dating the 36-year-old star, who found fame in the US legal drama Suits, since the summer of 2016.
Their 16-month whirlwind romance blossomed when they met through mutual friends in London and the pair have been almost inseparable in recent months, with Markle said to have virtually moved in to Harry’s home at Kensington Palace.
The Duke and Duchess of Cambridge said: “We are very excited for Harry and Meghan. It has been wonderful getting to know Meghan and to see how happy she and Harry are together.”
Ms Markle’s parents Thomas Markle and Doria Ragland issued a statement through Kensington Palace saying: “We are incredibly happy for Meghan and Harry.
“Our daughter has always been a kind and loving person.
“To see her union with Harry, who shares the same qualities, is a source of great joy for us as parents.
“We wish them a lifetime of happiness and are very excited for their future together.”
Ms Markle will become an HRH and a senior royal after marrying Harry and joining the Windsors.
She is expected to become a duchess - just like Kate Middleton did when she became the Duchess of Cambridge after saying her vows in 2011.
But unlike Kate, Ms Markle is not a future queen. With the arrival of the Cambridges’ children, Harry is too far down the line of succession to have a realistic prospect of being monarch.
Ms Markle will most probably become HRH the Duchess of Sussex, if Harry is made the Duke of Sussex by the Queen on the morning of his wedding.
The pair were secretly engaged earlier this month and rumours a wedding was imminent stepped up a gear when Harry took Ms Markle to meet his grandmother the Queen for tea at Buckingham Palace.
The prince had to obtain the monarch’s permission to wed Ms Markle - thanks to the Succession to the Crown Act 2013, which requires the first six people in the line to the throne to seek the monarch’s consent.
Ms Markle is a divorcee. In 2011 she wed film producer Trevor Engelson after dating him for six years, but the pair split amicably less than two years later.
Harry and Ms Markle made their first official public appearance together at the Invictus Games in Toronto - where the star is based - in September.
They arrived hand in hand to watch the wheelchair tennis and the tactile pair were clearly devoted to one another.
At the closing ceremony a few days later, the prince was spotted kissing his girlfriend on the cheek as they watched the show from the VIP box, with Ms Markle’s mother Doria Ragland.
Ms Markle was also reported to be leaving Suits, where she played paralegal-turned-lawyer Rachel Zane, after finishing the filming of Season 7.
When news of their relationship first broke in October 2016, smitten Harry was described as being happier than he had been in years.
Theatre dates followed, along with romantic African holidays and expeditions to see the Northern Lights, and a shopping trip to buy a Christmas tree together for Harry’s Kensington Palace pad.
As a newly-engaged couple, Harry and his bride-to-be may be invited to spend Christmas with Queen and the rest of the royals at Sandringham this year.
The pair share a strong bond through their philanthropy, with Harry supporting veterans and mental health organisations via his charity work, and Ms Markle pursuing her role as a humanitarian campaigner.
Even in its early days their union appeared to be a serious one. Six months in and just days after it became public they were dating, Harry took the unusual step of issuing a lengthy statement condemning media treatment of his girlfriend and criticising the “wave of abuse and harassment” she was facing.
It was Ms Markle who offered the biggest insight into their affair when she was interviewed by Vanity Fair magazine in September 2017 and revealed they were in love.
“We’re two people who are really happy and in love,” she said.
“We were very quietly dating for about six months before it became news and I was working during that whole time, and the only thing that changed was people’s perception.
“Nothing about me changed. I’m still the same person that I am, and I’ve never defined myself by my relationship.”
She added: “I’m sure there will be a time when we will have to come forward and present ourselves and have stories to tell, but I hope what people will understand is that this is our time.”