Obama said the operation carried out Sunday afternoon in northwest Pakistan resulted from "years of painstaking work" by intelligence agencies that yielded new clues to bin Laden's whereabouts starting last summer.
"I met repeatedly with my National Security team as we developed more information about the possibility that we had located Bin Laden hiding within a compound deep inside Pakistan," Obama said in an address from the East Room of the White House Sunday night.
"Finally, last week I determined that we had enough intelligence to take action and authorized an operation to get Osama bin Laden and bring him to justice," Obama said.
A senior administration official said key members of the national security team gathered in the White House situation room at 1 p.m. Sunday to monitor the operation, which was carried out on the ground by a small group of Navy SEALS.
Nearly three hours later, Obama was informed that bin Laden's body had been tentatively identified. The identity was later confirmed, likely through DNA testing.
"Today, at my direction, the United States launched a targeted operation against that compound in Abbottabad, Pakistan," Obama said. "A small team of Americans carried out the operation with extraordinary courage and capability. No Americans were harmed. They took care to avoid civilian casualties. After a firefight, they killed Osama bin Laden and took custody of his body."
The 40-minute operation was a helicopter raid launched from Afghanistan. One helicopter had a mechanical malfunction and had to be destroyed in the mission, an official said. No Americans were hurt or killed.
Officials said at least three others were killed besides bin Laden, including two of his couriers and one of his adult sons.
Tensions were high inside the White House situation room as the raid began to unfold, administration sources said. But the mood quickly shifted to jubilation once the helicopter returned safely to Afghanistan.
In his address, the president invoked the memory and imagery of the 9/11 attacks, and the "gaping hole in our hearts" that led to the international manhunt for bin Laden nearly a decade ago.
The president said the killing of bin Laden would resonate around the world with people who oppose terrorism, and he stressed that the U.S. did not target bin Laden because of his faith.
"The U.S. is not at war with Islam," Obama said, echoing a phrase also used by his predecessor President George W. Bush. "Bin laden was not a Muslim leader. He was a mass murderer of Muslims.
"His demise should be welcomed by all who believe in peace and human dignity," Obama said.
The president said that the development demonstrates America's resolve to uphold justice and would be particularly meaningful for families of the victims.
"We will be relentless in our defense of our citizens and our friends and allies," Obama said. "And on nights like this one, we can say to families who lost loved ones to al Qaeda's terror: justice has been done."