Under the terms of the deal, Voynov also will serve three years of probation.
Voynov, 25, was originally facing a felony charge of corporal injury to a spouse, stemming from his October arrest after the Russian Olympian allegedly kicked, punched and pushed his wife, Marta Varlamova, in their Redondo Beach bedroom after a fight that began at a party attended by other Kings players. He allegedly pushed her into a TV that opened a cut over her eye requiring eight stitches.
Voynov is suspended indefinitely by the league, and his reinstatement is not automatic. The NHL would have to conduct its own investigation before he is allowed to play again.
The Russian-born defenseman also is suspended by the Kings for sustaining a non-hockey-related injury.
"We believe the legal system has effectively resolved this matter and the punishment is fair and just," the Kings said in a statement. "Any act of domestic violence is unacceptable. As an organization, the prevention of domestic violence and the education of our players and employees is of paramount importance. We will continue to actively develop and implement a strategy to deliver this message."
Voynov would not comment as he left Los Angeles County Superior Court holding his wife's hand. He must begin serving his jail term by July 14.
"Mr. Voynov and his family are grateful that this matter is nearly at an end," Rolland Hedges, Voynov's agent, said in a statement. "Mr. Voynov accepts responsibility for his actions the night of the incident and will complete his sentence as required by the court."
According to Hedges, his client has not decided when he plans to report to jail to serve his time. That decision is expected to be made by Monday.
As for his potential future playing career, Hedges told ESPN.com that they have received no indication yet from the Kings on what they plan to do -- the team terminated Mike Richards' contract for a "material breach" while he is under investigation by Canadian authorities for an off-the-ice incident at the Canada-U.S. border -- but Hedges said that Voynov's priority will be to cooperate with the NHL's investigation process.
It was not immediately clear whether Voynov may face immigration issues -- deportation was a possible consequence of his sentence -- although that appears unlikely.
The case against Voynov became more difficult for prosecutors when his wife refused to testify.
Assistant District Attorney Frank Dunnick would not comment on whether her reluctance played a role in the plea deal, though he said it wasn't uncommon to have victims go silent in domestic violence cases. He said the outcome was similar to what other defendants get in such cases.
A judge had ruled that other witnesses could testify about statements Varlamova made when she sought medical treatment.
Varlamova said Voynov hit her in the face at the Oct. 19 party a few hours after the Kings won an afternoon game, Redondo Beach police Officer Gregory Wiist testified at a preliminary hearing. The abuse escalated at home.
Wiist found blood on a comforter in the couple's bedroom, a bloody handprint and blood on the floor.
"She was crying, sobbing," Wiist said, describing Varlamova at a hospital after the incident. "I saw tears streaming down her face. She was an emotional wreck."
Voynov told police his wife was injured getting out of bed, according to a police report.
Varlamova later wrote a letter to prosecutors saying her injuries were accidental. A judge didn't accept that evidence during the preliminary hearing and ordered her to seek counseling.
Varlamova was warned she could be held in contempt and fined for refusing to testify and was told it could affect her immigration status.
On Thursday, the couple entered the courtroom holding hands. Varlamova sat in the gallery with her lawyer and a Russian interpreter.
Voynov said few words through his own interpreter. He uttered "no contest" in Russian at the start and end of the brief proceeding.
The two-time Stanley Cup champ was indefinitely suspended by the NHL after his arrest and missed the final 76 games of the regular season while the case was pending.
It was one of the longest suspensions in NHL history and came at a time when professional sports leagues and teams were criticized for lax punishment for violence outside the arena of competition.
The defending champion Kings missed the playoffs this year.
The Kings confirmed June 24 that they had suspended their No. 2 defenseman because he was injured outside normal hockey training when he tore his right Achilles tendon earlier this year. He had surgery in March.
The move means Voynov's contract doesn't count against Los Angeles' salary cap.
Voynov must complete a yearlong domestic violence program and have no negative contact with his wife. If he violates any terms of probation, he could be sentenced to up to 364 days in jail.
Defense lawyer Pamela Mackey said it was a fair resolution for her client.
Judge Eric Taylor lifted an order barring Varlamova from communicating with her husband but recommended she continue counseling.
Information from The Associated Press was used in this report.