Kueng, 29, had pleaded guilty to one count of aiding and abetting in second-degree manslaughter in October as part of an agreement with prosecutors. A second charge of aiding and abetting in second-degree unintentional murder will be dismissed against Kueng as part of his plea agreement.
"We appreciate very much that Mr. Kueng plead guilty," said prosecutor Matthew Frank at the sentencing.
"We hope the conclusion of this case reaffirms that peace officers cannot treat citizens in crisis as non-people, or second-class citizens," Frank added.
The plea was announced just as a joint state trial for Kueng and Tou Thao, another officer, was to begin with jury selection.
"J. Alexander Kueng is now the second officer involved in Floyd's death to accept responsibility through a guilty plea. That acknowledgement hopefully can bring comfort to Floyd's family and bring our communities closer to a new era of accountability and justice," Minnesota Attorney General Keith Ellison said in an October statement on the plea deal.
Floyd's death ignited protests nationwide against police brutality and systemic racism.
"We must never forget the horror of what we all saw in that 9-minute video, and that there rightfully should be both accountability for all involved as well as deep lessons learned for police officers and communities everywhere," said the legal team for George Floyd's family, led by civil rights attorney Ben Crump, in an October statement on Kueng's plea deal in October.
Both Kueng and Thao, 34, are currently serving federal sentences after being convicted in February on federal charges of violating Floyd's civil rights.
The two were found guilty of depriving Floyd of his "constitutional right to be free from an officer's unreasonable force when each willfully failed to intervene to stop ... [Derek] Chauvin's use of unreasonable force."
Derek Chauvin, the officer who knelt on Floyd's neck, was found guilty on three counts in Floyd's death: Second-degree unintentional murder, third-degree murder and second-degree manslaughter for pressing his knee against Floyd's neck for more than 9 minutes.
He had been sentenced to 22.5 years.
Chauvin had additionally been sentenced to 21 years on federal civil rights charges in Floyd's death.
Thao waived a jury trial and his state charges will be decided by a judge. According to MPR, Judge Peter Cahill will review evidence received by Nov. 17 and has 90 days to decide the case, according to MPR News.
A third defendant, former Minneapolis police officer Thomas Lane, was also convicted on federal civil rights charges stemming from Floyd's death. Lane pleaded guilty to state charges of aiding and abetting second-degree manslaughter
The video in the player above is from a previous report.
ABC News' Bill Hutchinson contributed to this report.