The prosecution told jurors that Mr Chauvin had murdered Mr Floyd, but the defence said their client had correctly followed police training.
The court is being protected by barbed wire, high barriers and armed soldiers from the National Guard.
Cities across the country are bracing for protests regardless of the verdict.
On Monday, the prosecution and defence made their closing statements in a trial that lasted three weeks. The prosecution then had another opportunity to rebut defence arguments before the jury was sent to deliberate.
The jury will be sequestered to consider testimony from 45 witnesses, including doctors, use-of-force experts, police officers, bystanders and people who were close to Mr Floyd.
The defendant is charged with second-degree unintentional murder, third-degree murder and manslaughter. Mr Chauvin faces up to 40 years in prison if convicted of the most serious charge – second-degree murder.
A conviction on any of the counts against him will require the jury to return a unanimous verdict. A single juror holding out would result in a mistrial, but the state could then try Mr Chauvin again.
Of the 12 jurors, six are white, four are black and two are multiracial. Seven are women and five are men.