The townhouse, comprising five floors, features six en-suites, a gym, underground cinema and a staff room.
The new Georgian mansion is near to where Pippa, 38, and her sister the Duchess of Cambridge, 40, grew up in Bucklebury.
Pippa and James, a hedge fund manager, have just welcomed their third child Rose who was born last month.
Pippa first met James in 2007 during a visit to St Barts where the pair both stayed at luxury hotel Eden Rock.
Pippa has sold her five-floor Chelsea pad
Pippa and James welcomed their third child last month
The pair got married on May 20, 2017 with Prince George and Princess Charlotte as part of the bridal party.
Pippa and James now share three children – Arthur, three, Grace, one, and Rose, who is one month old.
Their new home in Berkshire is just a 20-minute drive from her parents Michael and Carole Middleton’s home.
The sale is said to have been carried out privately.
The new home in Berkshire is just 20 minutes from where Pippa’s parents live
Pippa and James got married in 2017
A local told the Daily Mail: “It’s a far more impressive property than any of those on the Windsor estate, apart from the castle.”
A removals lorry was seen outside the couple’s home in West London this week as the family prepare for the move.
James’s father, David Matthews, is Laird of Glen Affric, a 10,000-acre estate in Scotland.
Pippa is the sister of the Duchess of Cambridge
His parents also own the Eden Rock resort on the island of St Barts in the Caribbean.
James, whose brother is reality television star Spencer Matthews, is a former professional racing driver.
The new home is the subject of a multi-million-pound restoration by its previous owner.
Source: EXPRESS CO UK