Nicholas Sparks -- Wife Has Moved Out and Moved On

Nicholas Sparks and his wife may have announced their separation this week, but they are so far down the road to divorce she's already bought her own house ... TMZ has learned.

Catherine became the owner of a $1.1 million mansion on December 9. It's 2 1/2 miles from the Sparks family home, which makes sense ... they have 5 kids together. The house sits on 4 acres of lakefront property.

As TMZ reported ... Nicholas and Catherine signed a "postmarital agreement" back in August, which indicates they have reached a property settlement deal. They both waived their right to alimony.