Kevin Costner and Christine Baumgartner Finalize Divorce

Kevin Costner and Christine Baumgartner have settled their super bitter divorce and finalized the judgment ... TMZ has learned.

According to legal docs, obtained by TMZ, Kevin and Christine signed a Marital Settlement Agreement, which they filed with the court. Since more than 6 months have passed since Christine filed for divorce -- the required waiting time in California -- the case is over.

Details of the settlement are not yet available, but we're told the judge validated the prenup that became a big bone of contention during the divorce.

Both parties asked for joint custody of their 3 kids, and, as you know, Christine got $63,000 a month in child support. She was asking for an eye-popping $248,000 a month, but her justification was shaky, to say the least. One of the items she put in her expense declaration -- $100,000 for cosmetic surgery. BTW, before the child support ruling, Kevin offered her $75k a month.

Kevin and Christine personally signed the document signaling the settlement, along with their respective lawyers, disso queen Laura Wasser and Marisa Beuoy.

The document also says the parties waive the typical requirement of co-parenting classes.