According to the White House, Biden and Harris watched the verdict live from the private dining room just off the Oval Office. "And that is the reality of it".
Three other officers have been charged with aiding and abetting murder in the second degree.
US President Joe Biden and vice-president Kamala Harris phone called the Floyd family after the verdict, sharing their relief that there had been "some justice".
"George Floyd should still be alive - and we must keep fighting to dismantle systemic racism and fundamentally transform our justice system", Massachusetts US Senator Elizabeth Warren tweeted.
Floyd died last May after Chauvin, a 45-year-old now-fired white officer, pinned his knee on or close to the 46-year-old Black man's neck for about 9 1/2 minutes as Floyd gasped that he couldn't breathe and onlookers yelled at Chauvin to get off.More news: Chadian Military Picks Idriss Deby's Son As Replacement For Late President
People march near the Minnesota State Capitol to honor George Floyd on 19 March 19, 2021 in St Paul, Minnesota.
After nearly a month of the trial and ten hours of deliberation, the jury came to their verdict on the case.
But, accountability in this case does not bring George Floyd back, Massachusetts Attorney General Maura Healey said.
"They're a good family and they're calling for peace and tranquillity no matter what that verdict is", Mr Biden said.
The jury began deliberating Monday after almost a full day of closing arguments in which prosecutors argued that Chauvin squeezed the life out of Floyd last May in a way that even a child knew was wrong when he pressed his knee on a handcuffed Floyd's neck for several minutes.
Former Minneapolis police Officer Derek Chauvin has been convicted of murder and manslaughter in the death of George Floyd, the explosive case that triggered worldwide protests, violence and a furious reexamination of racism and policing in the U.S.More news: Alexei Navalny sent to prison hospital in Russian Federation
The defence countered that Mr Chauvin behaved as any "reasonable police officer" would, and sought to raise doubts about the cause of Mr Floyd's death, saying heart disease or even the exhaust fumes from the nearby police auto may have been factors. The Minneapolis police chief, Medaria Arradondo, was among a number of police supervisors and use-of-force experts who testified for the prosecution and told jurors that once Mr. Floyd stopped resisting, Mr. Chauvin should have lifted up his knee and moved him to his side.
Several families with small children are among those holding vigil for an announcement from the court.
"I don't have any doubt in you, God", she said. "We must not turn away, we can't turn away", he said. "This is the day that the Lord has made".
Ben Crump, one of the attorneys for George Floyd's family that helped settle a $27 million civil lawsuit last month, called the Derek Chauvin case a "turning point in American history for accountability of law enforcement", after the former Minneapolis police officer was convicted on all three counts in Floyd's death.
On trial wasn't just Mr. Chauvin, a 19-year veteran of the department before he was sacked last year.
National Guard troops had headed to downtown Minneapolis before the verdict was read. Some businesses are boarded up with plywood.More news: Boris Johnson visit to India cancelled due to COVID-19