Mohamed Noor, 36, is scheduled to be released from custody on Monday, according to online Department of Corrections records.
Noor was initially convicted of third-degree murder and manslaughter in the 2017 fatal shooting of Justine Ruszczyk Damond, a 40-year-old dual US-Australian citizen and yoga teacher who was engaged to be married.
But last year, the Minnesota Supreme Court tossed out his murder conviction and 12 and a half year sentence, saying the murder charge did not apply to the circumstances of this case.
He was re-sentenced to four years and nine months on the manslaughter charge.
In Minnesota, it is presumed that a defendant with good behaviour will serve two-thirds of a sentence in prison and the rest on supervised release, commonly known as parole.
The DOC's website says Noor will be on supervised release until January 24, 2024.
Damond's father, John Ruszczyk, said on Friday that the family was disappointed that Noor's third-degree murder conviction was overturned.
"His release after a trivial sentence shows great disrespect to the wishes of the jury who represented the communities of Minneapolis and their wish to make a statement about the communities' expectations of police behaviour and actions," Ruszczyk wrote in response to emailed questions from the Associated Press.
After his conviction, Noor began serving his time at Minnesota's maximum-security prison in Oak Park Heights but the Star Tribune reported he was transferred to a facility in North Dakota in July 2019 for his own safety.
Department of Corrections spokesman Nicholas Kimball said Noor is still out of state but did not specify where.
"For safety reasons, we aren't able to provide more detail than what is available on the public website, which is the scheduled date of release," Kimball said.
It was not clear whether Noor would return to Minnesota.
His lawyer, Tom Plunkett, declined to comment, saying, "at this point I just want to respect Mr Noor's privacy".
Damond's killing angered citizens in the US and Australia, and led to the resignation of Minneapolis' police chief.
It also led the department to change its policy on body cameras; Noor and his partner did not have theirs activated when they were investigating Damond's call.
Noor testified at his 2019 trial that he and his partner were driving slowly in an alley when a loud bang on their police SUV made him fear for their lives.
He said he saw a woman appear at the partner's driver's side window and raise her right arm before he fired a shot from the passenger seat to stop what he thought was a threat.
Damond was a meditation teacher and life coach who was killed about a month before her wedding.
Her maiden name was Justine Ruszczyk, and though she was not yet married, she had already been using her fiance's last name.
Her fiance, Don Damond, declined to comment on Noor's pending release but said during Noor's re-sentencing that he had forgiven the former officer and that he had no doubt Justine also would have forgiven him "for your inability in managing your emotions that night".
John Ruszczyk said in his email to the AP that his family believes state investigators and the Minneapolis Police Department did not fully co-operate with the investigation into his daughter's killing and he was disturbed by the agency's culture.
He said he believes the department accepts using violence as a way to control challenging situations, which he said contributed to her death.
"How could officers go out onto the streets in the roles of defenders of public safety and order with the attitude to their duties and obligations that allows them to shoot first and ask questions later?" he wrote.
Days after Noor's conviction, Minneapolis agreed to pay $US20 million ($A29 million) to Damond's family, believed at the time to be the largest settlement stemming from police violence in Minnesota.
