The Queen has appointed every prime minister since Anthony Eden in 1955, but Liz Truss will be the first invited to Scotland.
In a break with tradition, the new PM will not meet the Queen in London at Buckingham Palace.
On Tuesday the monarch will hold an audience with the next prime minister at Balmoral.
The Queen ascended to the throne in 1952, when Winston Churchill was prime minister. Here are images of her with all 15 leaders from her 70-year reign.