Around 100 people demonstrated outside the US embassy in Dublin today, demanding justice for George Floyd. A peaceful protest was also held outside the official residence of the US ambassador, Deerfield, in the Phoenix Park.
The 46-year-old African-American man stopped breathing after Minneapolis police officer Derek Chauvin was filmed kneeling on his neck. He has since been charged with third degree murder.
In the video, Mr Floyd can be heard telling police officers, "I can't breathe."
The incident has sparked violent protests across the US, with curfews overnight in dozens of cities amid growing unrest.
The demonstrators in Dublin carried signs saying 'I can't Breathe' and 'Black Lives Matter'.
Hundreds of people gathered in Trafalgar Square, London to protest against the death Mr Floyd.
Some London protesters, crowded together despite social distancing restrictions, held signs reading 'Justice for George' and 'Rest in power'.
Reverend Sally Hitchiner, associate vicar at St Martin-in-the-Fields church on Trafalgar Square, said she could see hundreds gathered for the protest from her workplace.
The 40-year-old told the PA news agency: "I'm very sympathetic to the issue but also surprised to see the strength of emotion that has gathered people together."
She said police appeared to be moving the crowd on from the square by early afternoon.
People also attended a protest rally against racism in front of the Brandenburg Gate in Berlin, Germany.
Dozens of demonstrators gathered in Kreuzberg district and in front of the American Embassy in Berlin yesterday and today.
Protesters chanted slogans in Toronto, Canada during a rally yesterday to protest the death of George Floyd as well as the death of a black woman who fell from her apartment balcony in the city last Wednesday while alone with police officers who had been called to her home.