Their romance was only confirmed last month when they were spotted holding hands at a White House Dinner party.
But Scarlett Johnansson, 26, and Sean Penn, 50, have decided to call it a day, according to US magazine People.
Rumours of a split were sparked when the blonde actress did not attend the Cannes Film Festival with Sean for his movie The Tree Of Life.
The pair were first linked when they took a whirlwind trip to Mexico after being spotted enjoying an intimate lunch together in LA.
Both representatives have declined to comment.
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