According to a legal filing, obtained by TMZ, the "Flip or Flop" star is single once more in the eyes of California. After filing for divorce in late 2020, a judge just signed off on the dissolution.

We're told she and Ant are going to be sharing custody -- both legal and physical -- of their 1-year-old son, Hudson. Christina has 2 other kids with her ex-husband, Tarek El Moussa.

Our sources say neither Christina nor Ant will have to give the other any dough going forward. It also seems they've privately hashed out who gets what assets and property.

Like we told you, Christina and Ant announced they were separating in September, before Christina formally pulled the trigger a couple months later with divorce papers. They first linked up in 2017 -- while she and Tarek were going through their own split at the time.

There wasn't anything scandalous that caused this break-up -- our sources had previously told us Christina and Ant had simply drifted apart ... so no harm, no foul, it seems.

Obviously, this is the bow tie on their relationship -- but things have been moving behind the scenes while this divorce got buttoned up with the courts. Remember, Christina already unloaded the Newport Beach home she and Ant were sharing during their marriage ... snagging a cool $5.3 mil for it after asking for about $6M at first.