The move comes just a day after she reached the second round of the French election, where she will face centrist Emmanuel Macron.
Le Pen told French TV she needed to be above partisan considerations.
Le Pen said her decision had been made out of the "profound conviction" that the president must bring together all of the French people.
"So, this evening, I am no longer the president of the National Front. I am the candidate for the French presidency," she said.