Pubs fell silent and busy streets drew to a standstill as more than 60 million people observed the “shared national moment of reflection”.
Inside Westminster Hall in London, where the Queen is lying in state, a long file of mourners came to a standstill.
People clapped and cried “God save the King” when the minute was up.
Big Ben tolled and activity once again resumed across Britain.
The moment of reflection comes ahead of the late monarch’s funeral, which is slated to begin around 11am on Monday time (8pm AEST).
King Charles III has hosted a reception for world leaders ahead of the funeral procession.
Up to 500 world leaders were set to attend the ceremony.
President of France Emmanuel Macron and US President Joe Biden are among the world leaders paying respect to the Queen.
Queen Elizabeth II died aged 96 peacefully at her Balmoral home on September 8.