Derek Chauvin, a veteran of the Minneapolis Police Department, faces murder and manslaughter charges for his role in the 25 May 2020 death of the 46-year-old Floyd.
Chauvin, who was fired from the police force along with three other officers, could be sentenced to up to 40 years in prison if convicted of the most serious charge -- second-degree murder.
"I have faith that he will get convicted," Philonise Floyd, brother of the dead man, said Sunday.
A defining moment in US history
The Minneapolis-based StarTribune newspaper called the trial "a defining moment in America's racial history".
The precise cause of George Floyd's death is expected to be the central issue in the case, and a key piece of evidence is likely to be the bystander-filmed video of his death that went viral and triggered a summer of anti-racism protests.
Chauvin was seen in the video kneeling on Floyd's neck for nearly nine minutes while arresting him for allegedly passing a counterfeit $20 bill.
While lying with his face in the street, the handcuffed Floyd repeatedly complained that he could not breathe.
Chauvin's attorney, Eric Nelson, is expected to argue that the officer was following police procedure and will claim that Floyd's death was due to an overdose of the drug fentanyl and underlying health conditions.
Conviction requires a unanimous verdict
Ben Crump, a lawyer for the Floyd family, said Sunday that the defense would attack Floyd's character in hope that "you forget what you saw on that video".
Opening arguments are to begin at 9:00 am Central time (1400 GMT) in a heavily guarded Minneapolis courtroom for a trial being closely watched around the world.
Fifteen jurors have been selected, though Hennepin County Judge Peter Cahill is expected to drop one juror on Monday and proceed with 12 and two alternates.
The panel seated after two weeks of jury selection is racially mixed: six white women, three Black men, three white men, two mixed-race women and one Black woman.
A conviction on any of the charges -- second-degree murder, third-degree murder or manslaughter -- will require the jury to return a unanimous verdict.
Proceedings are expected to last about a month.
