Members of Floyd's family, activists and other families of victims of police violence joined citizens in front of the courthouse in downtown Minneapolis where the Chauvin trial concluded a month ago.
Many carrying signs with pictures of Floyd, Philando Castile and other Black people killed by police.
The crowds shouted: "no justice, no peace!" and "Say his name" — chants linked to the BLM movement.
'It has been a painful year,' says Floyd's sister
Several local activists, members of Floyd's family and family attorney Ben Crump spoke at the event.
Floyd's sister Bridgett told the crowd on Sunday, "It has been a long year. It has been a painful year."
"I will stand and be the voice for him," she said. "I will stand and be the change for him."
Veteran campaigner Reverend Al Sharpton told the crowd that Floyd's killing was "one of the greatest disgraces in American history."
"What happened to George Floyd, as well as so many others, is driving change not only across America but the world," he said.
"They thought that they could get away with it, and you went to the streets, Black and white, young and old, in the middle of the pandemic" to call for justice, Sharpton said.
Further events honoring George Floyd
In New York on Sunday, Floyd's brother Terrence attended a Brooklyn gathering in his brother's memory organized by Sharpton. He asked supporters to keep the name of his brother "ringing" for other victims of police violence. "Breonna Taylor, Sean Bell, Ahmaud Arbery, you could go through the whole list. There's a lot of them."
Other events in Minneapolis ahead of the anniversary of George Floyd's death include a virtual "day of action" that encourages people to organize remotely. Two panels with Floyd family members and other activists are planned for Monday. On Tuesday, there will be a community festival and candlelight vigil.