Belgium's appeals court granted Delphine Boel the title 'Princess of Belgium' after the former monarch's DNA test proved that he was her father, her lawyers said in a statement, adding Ms Boel was "fully satisfied" with the ruling.
The DNA test revealed in January that Albert II is the biological father of Ms Boel, putting an end to her long-running paternity claim.
Albert, who abdicated six years ago in favour of his son Philippe, had long contested Ms Boel's claim.
As well as being recognised as a princess, Ms Boel will change her surname to her father's, Saxe-Cobourg.
Her two children Josephine and Oscar will also receive royal titles and the right to be referred to as his or her royal highness.
"A legal victory will never replace the love of a father, but does offer a sense of justice, further reinforced by the fact that many children who have gone through the same ordeal will find strength to face them there," Ms Boel's lawyers said.
The court's sudden ruling came as a surprise as its decision had been scheduled for October 29th. -Reuters
