Here are some of the tributes to Britain's longest-serving monarch, who is also head of state in 14 Commonwealth countries around the world:
'Grace, dignity, and dedication'
At the United Nations, the Security Council honored her passing Thursday with a minute of silence.
Queen Elizabeth had been "widely admired for her grace, dignity and dedication around the world. She was a reassuring presence throughout decades of sweeping change," UN Secretary-General Antonio Guterres said.
'Constant presence in our lives'
Canadian Prime Minister Justin Trudeau said Elizabeth, who was head of state of Canada, will "forever remain an important part" of the country's history.
"She was a constant presence in our lives -- and her service to Canadians will forever remain an important part of our country's history," he said.
In another key member of the British Commonwealth, Australia's Prime Minster Anthony Albanese -- an avowed republican -- paid tribute to her "timeless decency" and said her death marked the "end of an era."
"Australian hearts go out to the people of the United Kingdom," Albanese said. "An historic reign and a long life devoted to duty, family, faith and service has come to an end."
The smallest members of the Commonwealth also paid their respects.
David Burt, premier of the tiny island of Bermuda, which is still a British overseas territory, hailed her "life of undimmed duty," adding that she was also "a mother, grandmother and great-grandmother and her family is now mourning that loss."
'Unmatched dignity and constancy
US President Joe Biden called her the first British monarch to make a personal connection with people around the world, as he ordered flags at the White House and government buildings flown at half-staff in her honor.
"Queen Elizabeth II was a stateswoman of unmatched dignity and constancy who deepened the bedrock alliance between the United Kingdom and the United States. She helped make our relationship special," he said.
The pope prays
In the Vatican, Pope Francis said he was "deeply saddened" by her death and would pray for the late queen as well as her son, the new King Charles III.
'Elizabeth the Steadfast'
Leaders of the European Union expressed regret at the death of the queen, who was head of state throughout Britain's entire EU membership and eventual departure.
"Once called 'Elizabeth the Steadfast', she never failed to show us the importance of lasting values in a modern world with her service and commitment," said EU council president Charles Michel.
Philippe, King of the Belgians and who has a close family link to the British aristocracy, hailed the queen as "an extraordinary personality."
"The United Kingdom has lost an exceptional monarch who left a deep mark on history," the Belgian palace said in a statement.
King Willem-Alexander of the Netherlands, Queen Maxima and Princess Beatrix called her "steadfast and wise."
"We feel a strong bond with the United Kingdom and its royal family, and we share their sorrow at this time. We are very grateful for our countries' close friendship, to which Queen Elizabeth made such an unforgettable contribution," they said.
King Carl XVI Gustaf of Sweden called her "a good friend of my family and a link to our common family history."
While Spanish King Felipe VI said she "wrote the most relevant chapters of history."
Ireland's President Michael Higgins called Queen Elizabeth II "a remarkable friend" who had "great impact on the bonds of mutual understanding between our two peoples".
"As we offer our condolences to all our neighbours in the United Kingdom, following the loss of a remarkable friend of Ireland, we remember the role Queen Elizabeth played in celebrating the warm and enduring friendship" between both countries, he said.
Scottish leader Nicola Sturgeon, who supports independence for Scotland from the rest of Britain, called her death "a profoundly sad moment for the UK, the Commonwealth and the world."
"On behalf of the people of Scotland, I convey my deepest condolences to The King and the Royal Family," Sturgeon said.
Accolades also poured in from South Asia, where Britain was the colonial power up until just before Elizabeth's reign began.
India's Prime Minister Narendra Modi said he was "pained" by her death.
Queen Elizabeth "provided inspiring leadership to her nation and people", Modi tweeted, adding she "personified dignity and decency in public life".
In Pakistan, President Arif Alvi hailed Queen Elizabeth as a "great and beneficent ruler."
She "would be remembered in golden words in the annals of world history," he said.
'Marked her century'
French President Emmanuel Macron hailed the queen as "a friend of France... who marked her country and her century as never before".
"Her Majesty the Queen Elizabeth II embodied continuity and unity in the British nation for more than 70 years," the French leader tweeted.
Italian Prime Minister Mario Draghi said she "guaranteed stability in moments of crisis and kept alive the value of tradition in a society in constant and profound evolution."