The couple share a son together and first announced their engagement last February.
Mr Johnson’s new wife took on his name following the ceremony to become Carrie Johnson.
The marriage will allow her to taken on a more public role as the wife of the UK Prime Minister.
Carrie was absent for the last G7 meeting in Biarritz, France, in 2019, with No10 blaming work commitments for the failure to be in attendance.
This time around she will play a central role in forging relationships with the UK’s international allies.
Next weekend Mrs Johnson will host the US First Lady, Jill Biden, along with other leaders’ significant others in Carbis Bay for the international summit.
No10 is eager to woo Mr and Mrs Biden as the UK seeks to secure a US trade deal in the near future.
The American President has ruled out doing a deal while the US is still recovering from the coronavirus pandemic.
While the Prime Minister seeks to build consensus among his opposite numbers on a range of international issues including climate change and the pandemic, Mrs Johnson will seek to forge personal bonds.
Spouses are usually seen touring art galleries, museums and local attractions during the G7.
Mrs Johnson has faced accusations of being too heavily involved in the running of her husband’s Government by critics.
A former head of communications for the Conservative party, Mrs Johnson has a number of close friends and allies within the Government.
Earlier this year Downing Street was forced to deny claims she had a central role in the running of the country.
It came after The Bow Group think tank, which counts Tory MPs and peers among its supporters, called for an inquiry to “examine the full spectrum of Ms Symonds’s interference and influence”.
Allegra Stratton, who was appointed as the Prime Minister’s press secretary last autumn, is a close friend to Mrs Johnson.
Allies Henry Newman and Baroness Finn have also been appointed as Downing Street aides in recent months.
Last week the Prime Minister’s former chief aide, Dominic Cummings, accused his ex-boss of being slow to respond to the coronavirus pandemic last spring due to dealing with his partner who was going “crackers” about a story that had been printed in The Times about the couple’s pet dog.