The BBC are reporting that Osama Bin Laden has been killed in a US special forces raid on a compound in Abbottabad, 60 miles north-east of Islamabad.
After a “firefight” Bin Laden was killed and his body taken by US forces, the president said.
Mr Obama said “no Americans were harmed”.
US officials said Bin Laden was shot in the head after resisting.
US media reports said that the body was buried at sea to conform with Islamic practice of a burial within 24 hours and to prevent any grave becoming a shrine.
Giving more details of the raid, one senior US official said a small US team had conducted the attack in about 40 minutes.
Three other men were killed in the raid – one of Bin Laden’s sons and two couriers – the official said, adding that one woman was also killed when she was used as “a shield” and two other women were injured.
One helicopter was lost due to “technical failure”. The team destroyed it and left in its other aircraft.