The Braveheart star indicated in his own court filings that the couple separated in 2006.
Throughout the 31-year marriage, which produced seven children, Mel directed, invested and starred in movies such as “The Passion of the Christ,” which grossed more than $600 million alone.
He also invested heavily in real estate, including an island in Fiji he bought for $15 million in 2005.
People also reports that Robyn, a former dental nurse, is entitled to half of any film residuals Mel receives for the rest of his life.
The couple”s divorce has been more low key than Mel”s custody battle with Russian musician Oksana Grigorieva.
The 55-year-old actor agreed in August to pay Oksana £481,000 to settle a bitter dispute and split custody of their daughter.
The divorce, which will take effect in January is believed to be the biggest celebrity divorce payout in Hollywood history.
Director Steven Spielberg paid an estimated $100 million to Amy Irving in their 1989 divorce.