The report, which cited documents seized at the Pakistan compound where bin Laden was killed by US forces, said the Al-Qaeda leader also sought to kill General David Petraeus, who then headed international forces in Afghanistan.
Bin Laden wanted to kill the US president because "Obama is the head of infidelity and killing him automatically will make (Vice President Joe) Biden take over the presidency," according to a document purported to come from the compound.
"Biden is totally unprepared for that post, which will lead the US into a crisis. As for Petraeus, he is the man of the hour, and killing him would alter the war's path in Afghanistan."
The scheme was described in one of the documents taken from bin Laden's compound by US forces on May 2, 2011, the night he was killed, and made available to Washington Post opinion writer David Ignatius.
"They have been declassified and will be available soon to the public in their original Arabic texts and translations," Ignatius wrote.
The documents said bin Laden hoped the attacks on Obama and Petraeus would be carried out Pakistani militant Ilyas Kashmiri, who is believed to have been killed in a US drone attack last June.
The report said US analysts see little possibility that the plots could have been carried out.