Maybe the biggest celebrity house sale of the year is going down in Bev Hills, because TMZ has learned Adele is about to become the owner of Sylvester Stallone's awesome estate, and she's getting it for a steal.
Sources with direct knowledge tell TMZ ... Adele is in escrow for Sly's massive home, tucked away inside Beverly Park -- a super-exclusive, gated community riddled with celebs.
Now get this ... our sources say Adele is paying $58 mil for the property.