The 28-year-old Swedish actress and Michael, 40 – who have been dating since 2014 – have apparently decided to tie the knot in a top-secret ceremony on the Spanish island of Ibiza in October.
A source explained: “The details of the party are being kept under lock and key.”
However, it’s been claimed Michael will pay for the entire party to stay at a five-star resort on the island, which is famous for its legendary nightlife.
The insider told The Sun newspaper: “Guests have been told to arrive in Ibiza on a certain date and they will then be collected and taken to the hotel.
“He’s splashing out big time and it’s going to be the party of the year.”
The Hollywood duo have been tight-lipped about their romance ever since they met on the set of the Derek Cianfrance-directed drama ‘The Light Between Oceans’ three years ago.
Despite this, Michael revealed in an interview last year that their relationship “just happened”.
He shared: “It just happened. It’s good that it happened. It is what it is.”
Meanwhile, Alicia recently revealed she has “always wanted” to have children.
The Academy Award-winning actress – who has previously starred in films such as ‘Ex Machina’ and ‘The Danish Girl’ – admitted she would love to start a family with Michael.
She explained: “I don’t even have children, and it’s the wonder of my world. I’ve always wanted kids. I’ve never been pregnant, but I hope to have a family one day.
“It’s both the expectation and knowing that it should be the greatest experience of my life – and suddenly from one day to another, it’s a reality; it’s a new chapter of your life.”