Hundreds of people gathered in London's Trafalgar Square on Sunday, following demonstrations in Berlin and Toronto.
"Say his name," some shouted in London, while other held placards reading "I can't breathe," the last words uttered by Floyd, 46, before he died after a Minnesota police officer, Derek Chauvin, kneeled on his neck during an arrest last Monday.
Chauvin was charged with third-degree murder and manslaughter on Friday, but riots across the U.S. continued over the weekend.
In London, protesters defied laws banning the gathering of large crowds during the coronavirus pandemic and many protesters were not social distancing, although a large number were wearing masks.
In Berlin on Saturday, thousands of protesters gathered outside the U.S. embassy, some holding signs that read "Justice for George Floyd" and "I Can't Breathe." Many also chanted "Black Lives Matter."
In Canada, thousands turned out in Toronto's Christie Pitts Park on Saturday, before they marched to police headquarters.
As well as protesting Floyd's death, many vented their anger at the death of Regis Korchinski-Paquet, who died in a fall from her 24th-floor balcony after police officers were called to her home.
Toronto Police are investigating the incident.
China, Iran and Russia voiced support for the protesters and criticized the U.S.
In China, state media highlighted the "double-standards" of U.S. support for pro-democracy demonstrators in Hong Kong, while quelling unrest in the United States.
Chinese foreign ministry spokesman Zhao Lijian on Monday called discrimination against ethnic minorities “a chronic disease in American society," according to China's People's Daily newspaper.
The Russian ministry of foreign affairs tweeted on Saturday: "American police commit high-profile crimes all too often, ... U.S. authorities should meticulously investigate the murder of George Floyd."
Iranian Foreign Minister Javad Zarif shared a satirical post on Twitter, crossing out accusations toward Iran in a U.S. press release about the 2018 protests in the country with red ink and redirecting them back toward America.
China, Russia and Iran have all been criticized for their own treatment of protesters.
Russian authorities have been accused by Amnesty International of refusing to authorize public assemblies, breaking up peaceful gatherings and prosecuting protesters as people took to the streets to demand fair elections last year.
In Iran, security forces used lethal force unlawfully to crush protests, killing hundreds, and arbitrarily detaining thousands of protesters to quash unrest in 2019, according to the human rights organization.
The group said in China, where there is a systematic crackdown on dissent, peaceful protesters in Hong Kong have been attacked with tear gas and batons, arrested under vague charges and beaten in custody.
Reuters contributed to this report.