Larry King is done sleeping alone -- TMZ has learned CNN's most notorious playboy is moving back in with his wife Shawn Southwick ... at least for now.
Sources close to the couple tell us King is checking out of the hotel where he's been staying and heading back into the couple's Beverly Hills mansion today .... to give the whole "living together" thing another test run.
We're told both sides have agreed to a one-week trial ... but it could go longer if things go well.
This is the third time Larry and Shawn extended their deadline for moving forward with the divorce. Today was supposed to be do-or-die decision-making time.