Baumgartner filed for divorce on May 1 after 18 years of marriage to the 'Yellowstone' star.
Kevin Costner and his estranged wife, Christine Baumgartner, have settled their divorce, ET can confirm.
"Kevin and Christine Costner have come to an amicable and mutually agreed upon resolution of all issues pertaining to their divorce proceedings," a rep for Kevin tells ET in a joint statement for the duo.
The Yellowstone star and Baumgartner have been locked in a contentious divorce since the latter filed for divorce on May 1 after 18 years of marriage. According to court documents, obtained by ET, Baumgartner cited irreconcilable differences as the reason for the dissolution of the marriage, and she listed April 11 as the date of separation.
One day after Baumgartner, 49, filed for divorce, a rep for the Yellowstone star intimated he was dragged into a divorce.
"It is with great sadness that circumstances beyond his control have transpired which have resulted in Mr. Costner having to participate in a dissolution of marriage action," the statement read from Costner's rep to ET.
In one of her more recent court filings, Baumgartner shared that she met Costner on a golf course when she was 18. It's been reported that the actor, who at the time was married to his first wife, Cindy Silva, was on the golf course rehearsing for his sports comedy, Tin Cup, in the early 1990s.
According to Baumgartner, they started dating some six years later, in 1999, before tying the knot in 2004 at his second home in Aspen, Colorado. Costner was married to Silva from 1978 until their (reportedly very costly) divorce in 1994. They share three adult children -- Annie, Lily and Joe -- in their 30s. Costner also shares an adult son, Liam, from his previous relationship with actress Bridget Rooney.
The duo got married at Costner's sprawling Dunbar Ranch in Aspen, Colorado.
Costner became a father for the fifth time when Baumgartner gave birth to their son, Cayden, in May 2007. Baumgartner then gave birth to their second son, Hayes, in 2009, and they welcomed their daughter, Grace, in 2010.
Baumgartner's filing for divorce seemingly came out of nowhere, less than three months after Costner boasted that his wife had thrown him and Golden Globe Awards watch party as he unboxed the Golden Globe he won for Best Actor in a Drama Series for his role as the patriarch, John Dutton, in the Paramount hit show Yellowstone.
After she filed for divorce, Costner responded with his own legal documents, declaring that he also wanted joint custody of their children and that they had a prenuptial agreement. The prenuptial agreement would ultimately become a strong point of contention throughout the proceedings.
Amid the ongoing divorce, Baumgartner filed legal documents and brought up Costner's exit from Yellowstone while explaining "our separation."
"I have avoided being public about the reasons for our divorce," Baumgartner said in the court documents, obtained by ET. "I have done this to protect our family's privacy. I did not pressure Kevin to leave the Yellowstone show. Kevin's public attacks on me are harmful for our family. I believe they are meant to pressure me to move out without a temporary child support agreement in place."
Baumgartner also claimed that based on his 2022 income, Costner should fork over $248,000 per month in child support. She said she was willing to move out of the primary residence, but only once Costner agreed to provide her child support request.
She added that it's her "desire to set up a suitable separate household that is at least somewhat commensurate with the children's accustomed lifestyle."
As for Costner, he responded, essentially saying it's an outrageous figure for a number of reasons.
In documents his lawyer filed in court, and obtained by ET, Costner said Baumgartner's list of the children's "needs" for purposes of child support is "inflated and grossly inaccurate." He claimed Baumgartner was "fundamentally dishonest as to certain items included in her calculation of the children’s 'reasonable' needs, such as private school tuition for two of the children (failing to mention that only Grace will continue private school), and her own personal, non-child related expenses, such as extensive plastic surgery for herself in 2022."
"The children do not use the services of private trainers, only Christine does," Costner continued in court documents. "The plastic surgery expenses of $188,500/month belong to Christine – not the children. And Christine should know which credit card expenses were for her and which were for the children, but not even a minimal effort is made to allocate them accurately."
The parties went to court on Aug. 31 and Sept. 1 for hearings set to establish how much Costner should have to pay Baumgartner in monthly child support. Baumgartner took the stand to make her case and, at various times, grew emotional. For example, she choked back tears when questioning shifted from the Yellowstone star's beach club estate to his expansive ranch in Aspen, Colorado, where the kids have vacationed on numerous occasions and consider the estate a special place.
An eyewitness told ET that Baumgartner "started tearing up and reached for a tissue" when that portion of the questioning began. A 30-second pause ensued before the judge called for a five-minute break.
After a contentious two-day hearing, the judge sided with Costner on Sept. 1 and ordered that his monthly child support payments to Baumgartner be significantly reduced -- from $128,000 per month to $63,209.
Days later, Judge Thomas P. Anderle shared a 17-page summary of the child support case that explained the reasons behind his conclusions that ultimately gave Costner a considerable victory.
The judge said factoring Costner's Yellowstone salary to determine the amount he should have to pay her in monthly child support "would be unjust and inappropriate in this case." Costner had previously argued that his Yellowstone salary -- reportedly over $1 million per episode -- was a "complete aberration, and provided Kevin with an unusually high level of income -- a level he has never had in the past."
The judge added, "The court did not find Christine's theory of the case intellectually dishonest; but it was not persuasive; it did not preponderate."
The judge sanctioned Baumgartner and ordered her to reimburse Costner the $14,237.50 to cover his attorney's fees after he said he was forced to file a motion to compel because he claimed she refused to answer, "without justification," basic discovery.
Less than a week later, Baumgartner went to court and requested that Costner fork over nearly a million dollars to cover her attorney's fees and forensic accounting fees. Costner blasted the request as "outrageous" and "nonsensical."
Baumgartner, in her request, claims she needs $575,000 in attorney's fees and $280,000 in expert costs to prepare for the upcoming trial to settle their combative discord over whether the spousal support waiver in their premarital agreement is enforceable.
In court documents, obtained by ET, the $885,000 request is to cover 1,106 hours of attorney time at a rate of $800 per hour "simply to prepare for and argue the issue of the validity and enforceability of the spousal support limitation in the PMA now."
As for the forensic accounting, Costner claims that "the bulk of discovery has already been conducted with document production and deposition of the parties on the issue of child support and thereby gross cash flow for support."
"Simply put," Costner's documents state, "Christine fails to provide the court with any evidence that 1,106 hours of attorney time at $800 per hour is necessary to prepare" for this upcoming trial. Costner also calls out any future forensic accounting work needed -- and the money needed to pay those fees -- as either irrelevant or already completed.
As ET previously reported, Costner accused Baumgartner of using "stalling tactics" to drag out the tumultuous divorce battle. His legal team also slammed Baumgartner's claim that she did not understand their prenup agreement when she signed it, calling the so-called tactic "gamesmanship of the worst sort." He added that this "silly rhetoric ... just reinforces the game playing."
Costner was represented by go-to Hollywood divorce attorney Laura Wasser, who has often settled complex celebrity cases.