Truss was elected the head of the UK's Conservative Party on Monday after defeating former chancellor of the exchequer Rishi Sunak.
Truss became the first prime minister to be appointed by the Queen in Scotland, and not at Buckingham Palace, as tradition requires.
After meeting the Queen, the new prime minister will return to London and speak outside the Downing Street office.
Forty-seven-year-old Liz Truss became the third female prime minister of the UK.
Truss defeated Rishi Sunak through a postal ballot of all Conservative members. She secured 81,326 votes while Sunak got 60,399 votes.