By Agence France-Presse
The couple, given the titles the Duke and Duchess of Sussex after marrying in Windsor in May, will live in Frogmore Cottage, a two-storey stucco-faced house in Windsor Home Park close to the castle.
They will relocate to their new home, around 20 miles (32 kilometres) southwest of London, "as they prepare for the arrival of their first child," the palace said in a statement.
"Windsor is a very special place for their royal highnesses and they are grateful that their official residence will be on the estate," it added.
Prince Harry and Meghan, who returned earlier this month from a 16-day tour Pacific tour, currently live in Nottingham Cottage on the grounds of Kensington Palace in west London.
Described as cosy and "modest", it consists of two reception rooms and two bedrooms.
The Palace said the couple's office would remain there.
It provided no further details on the new official residence.
Historic England, a public body which maintains a register of old buildings given special protections, lists Frogmore House in its Grade II category.
The status is awarded to just 5.8 percent of approximately 500,000 listed buildings in England, marking them out as particularly important sites.
The organisation dates the cottage back to the early 19th century but does not detail how many bedrooms it contains.
It sits on the grounds of the far grander Frogmore House, built in 1680-84 and a royal residence since 1792 -- and where Harry and Meghan had their evening wedding reception.
"The name derives from the preponderance of frogs which have always lived in this low-lying marshy area," according to the royal family's website.