The Queen will meet the new prime minister on Tuesday September 6 at Balmoral in Scotland, a spokesperson has said.
It will be the first time she has conducted the appointment not at Buckingham Palace in London.
Before meeting Liz Truss or Rishi Sunak, the Queen will hold a meeting with Boris Johnson as he leaves office earlier in the day.
Traditionally the outgoing PM travels the short distance from N0.10 to the Palace in London to resign.
The incoming prime minister meets the Queen and then dives to Downing Street to takeover.
But next week the formal handover of power will require a 1,000 mile round trip for both.
The decision was taken at this stage in order to provide certainty for the PM’s diary.
The Queen has been experiencing episodic mobility issues, and if they returned next week it would mean alternative arrangements having to be made at the last minute.
Truss is the clear frontrunner in the Tory leadership race, with the winner due to be announced on Monday September 5.