The Oscar-winning actress filed a divorce petition in Los Angeles Superior Court on Wednesday, Nov. 8, citing "irreconcilable differences," according to documents found on TMZ.com.
She's seeking joint custody of their two children -- Ava, 7, and Deacon, 3 -- primary physical custody and sole use of the family residence, with Phillippe given visitation rights.
She's also asking not to have to give her estranged husband spousal support. Since the couple didn't sign a prenup, according to California law, they ought to split their assets equally, which would make Witherspoon the loser as the higher wage earner.
Neither party has commented specifically on the reasons for the split. Rumor has it that Phillippe had an affair with his "Stop Loss" co-star Abbie Cornish, who denies the affair. Recently, Phillippe vaguely told People, "I'm not a perfect person, but I'm not guilty of a lot of the things I have been accused of. My priority is and always has been the health and safety of my family."
Phillippe, 32, met Witherspoon, 30, at her 21st birthday party. They married and co-starred in "Cruel Intentions" in 1999.
Witherspoon won an Oscar in March for "Walk the Line," while her husband co-starred in the ensemble drama "Crash," which won best picture that same night. He currently can be seen in Clint Eastwood's "Flags of Our Fathers."