Elizabeth and Philip's marriage lasted 73 years, until his death in 2021. The late Queen spoke of how much she missed her "beloved" husband and this memorial design brings them together, with figures of the couple and a Prince Philip gate.
There is no date yet set for the monument to be completed. And the final cost has still be decided, with a budget previously said to be between £23m and £46m.
The anti-monarchy campaign group, Republic, called for the royals to pay for the memorial rather than the government. "They can pay for their own statue," said the group's chief executive, Graham Smith.
The design will see the re-landscaping of a section of St James's Park, with a bridge, two new gates, and two gardens, as well as statues of the Queen and the Queen with Prince Philip.
Lord Foster said it was an "honour and a privilege" for his team to carry out this project, which "stretched the boundaries of art and technology".
The leading architect's previous work has included the Gherkin office tower and the Great Court of the British Museum in London, and the Reichstag dome in Berlin.
He said the memorial was a creative attempt to convey the "values she represented" to the "many people who are passing through the park".