Maria Shriver has filed for divorce from Arnold Schwarzenegger in Los Angeles Superior Court.
The filing comes about six weeks after the former governor confirmed he fathered a child with a former housekeeper.
The divorce filing cited unspecified irreconcilable differences.
It did not list a date of separation.
The filing, which Ms Shriver signed nearly two weeks ago, signals an end to a union that began with a storybook wedding on a spring day in 1986 in Cape Cod and brought together a bodybuilder and rising action star and a princess of the Kennedy clan, herself an up-and-coming network newscaster.
Ms Shriver’s filing does not indicate the couple had a premarital agreement.
That means Schwarzenegger’s earnings from a career as a Hollywood megastar, which allowed him to forgo a salary as governor and commute by private jet to Sacramento, likely will be evenly divided with his estranged wife.
Ms Shriver is seeking spousal support but any amount would be determined later, either through a settlement agreement or by a judge. The divorce is expected to be handled mostly behind closed doors.
Several of Schwarzenegger’s biggest hits, including 'Predator', 'True Lies' and the blockbuster sequel 'Terminator 2' were made during his marriage to Ms Shriver.
Ms Shriver became an award-winning television journalist but put her career on hold when Schwarzenegger ran for governor.
Economic disclosure forms filed when Schwarzenegger left as California governor in January show he has interests in at least eight entities each worth $1m or more. An exact tally of his wealth is impossible to calculate.
The forms also show he still retains rights to intellectual property from his days as a fitness guru and movie star.
Ms Shriver’s holdings are more modest but are listed in the disclosure as being worth more than $1m.
Ms Shriver and Schwarzenegger have four children together, including two sons who are still minors. Ms Shriver’s petition seeks joint custody of the teens, who are 17 and 13.
Ms Shriver stood by her husband’s side as he ran for California’s governorship in 2003, even after the Los Angeles Times reported accusations by several women that they had been groped by the movie star.
Schwarzenegger later said he “behaved badly sometimes” and was twice elected to the governorship.