Angelina Jolie alleged the judge who oversaw her child custody case was “biased” and favored her ex-husband Brad Pitt— and now the “Maleficent” actress is using her experience to push legislation to check “corrupt” officers of the court.

In a two-page letter dated Sept. 29 and obtained by The Post, the actress and former Goodwill Ambassador urged California Gov. Gavin Newsom to support “Piqui’s Law,” which would require domestic violence training for judges, mediators and other court professionals on the effects of child abuse and trauma.

A source close to Jolie told The Post the actress is pushing for the legislation after the trauma she encountered under Los Angeles Judge John W. Ouderkirk, who refused to allow her kids to testify about domestic violence they experienced at the hands of their father.

“This is personal to her, and for good reason,” a source close to Jolie told The Post. “Look at what she faced from a biased judge who was removed by the appellate court for his corrupt and secretive financial dealings with Brad Pitt’s team that violated judicial ethics in her family’s case, and who refused to review evidence of domestic abuse.

“It’s no surprise she has taken on this specific issue. Their whole family is a victim of system failure. She has been fighting privately for her family and publicly for other families for years.”

Sources close to Brad Pitt, however, told The Post Jolie is using “her usual tactics” to “misrepresent the truth” and damage the reputation of the judge and other professionals who have testified against the actress.

Ouderkirk, a retired private judge who actually officiated the former couple’s nuptials, ruled in May 2021 that the couple would maintain 50/50 custody of their children.

The couple have five children— Maddox, 22, Pax, 19, Zahara, 18, Shilo, 17, and twins Knox and Vivienne, who are 15. The actress said Ouderkirk denied her children the opportunity to testify even though California law allowed children 14-years old and older to do so.

Jolie challenged the judge’s tentative custody decision and filed a petition in the appellate court to remove Ouderkirk from the case.

The appellate court in July 2021 ruled Ouderkirk should be disqualified from the case because the retired judge didn’t sufficiently disclose business relationships with Pitt’s attorneys.

However, sources close to Pitt’s legal team told The Post the 2021 appellate court ruling was based on a “technical procedure,” and had nothing to do with the facts related to the custody case.

“Judge Ouderkirk was not in business with anyone,” sources close to Pitt’s legal team said. “Like other private judges, he was engaged by both Ms. Jolie’s and Mr. Pitts attorneys on other cases, which he disclosed.

“It’s disappointing but not surprising that she would continue to manipulate the media and the public with [Donald] Trump-like distortions and to deliberately make misrepresentations without any regard for the damage it causes to innocent third-parties just trying to do their jobs.”

Sources close to Pitt’s team added, “While the legislation she is supporting is potentially very viable, it has nothing to do with her custody case. It is inexplicable why she would use her advocacy for another defamatory effort to disregard all the objective facts in order to advance her own interest.”

If passed, Piqui’s Law— named after a 5-year-old boy who was killed by his father in 2017— also would prevent abused children from being separated from their non-violent parent, as well as block children from going into reunification camps.

During the nearly five-year custody battle, Jolie fought to maintain custody of the children after a 2016 incident that ultimately broke the family apart.

The 59-year old “Fight Club” star allegedly flipped out during a Sept. 14, 2016 flight where Jolie claimed her then-husband, who had been drinking, took her to the restroom, “grabbed her by the head, shaking her,” according to an FBI report obtained by Page Six.

The report also said Pitt also shook Jolie by the shoulders as they argued over one of their children.

She alleged that he punched the ceiling of the plane four times after telling her, “You’re f—ing up this family.”‘ When the kids asked, “Are you OK, Mommy?,” Pitt allegedly replied: “No, she’s not OK, she’s ruining this family, she’s crazy.”

One of the children — whose name was redacted from the report — yelled, “It’s not her, it’s you, you p—k!,” according to the report. Pitt then allegedly ran toward the child, but Jolie held him back, suffering injuries to her back and elbow in the process.

Six days after the flight, Jolie filed for divorce. However, the FBI ultimately did not pursue charges against Pitt.

A source close to Jolie said the judge’s decision not to allow her children to testify should not happen to other children, and Piqui’s Law would protect that right.

“As a reminder, to this date, Pitt has still not ever denied his abusive behavior,” the source said. “New training for judges is absolutely necessary. If this happened to Jolie in her court case, just imagine what is happening all over the country.”

A source close to Pitt said the “Bullet Train” actor has acknowledged he was wrong in regards to the plane incident, but pointed no charges were filed against him.

“Brad has acknowledged he was wrong concerning his behavior on the plane and authorities who reviewed the matter decided to not press charges,” the source said. “Those FBI reports were introduced into evidence in the custody hearing, where he was still granted 50/50 custody.

“Anyone who testified or argued against her, she has tried to destroy. These defamatory comments against Judge Ouderkirk are demonstrably false, and she has even gone after a child evaluator who testified in the case.”

The legal battle between the two stars is far from over as they continue to fight over the French vineyard they once shared. A hearing in Los Angeles is scheduled for that civil case this week.