The Nobel Committee said he was awarded it for “his extraordinary efforts to strengthen international diplomacy and co-operation between peoples”.
“His diplomacy is founded in the concept that those who are to lead the world must do so on the basis of values and attitudes that are shared by the majority of the world’s population” said the Norwegian committee.
There were a record 205 nominations for this year’s prize.
Here are a few reactions from around the world:
Shimon Peres: “Very few leaders if at all were able to change the mood of the entire world in such a short while with such profound impact. Under your leadership, peace became a real and original agenda.”
Taliban spokesman Zabihullah Mujahi: “We condemn the award of the Nobel Peace Prize for Obama, We have seen no change in his strategy for peace. He has done nothing for peace in Afghanistan”
Hamid Karzai’s spokesman Siamak Hirai: “His hard work and his new vision on global relations, his will and efforts for creating friendly and good relations at global level and global peace make him the appropriate recipient of the Nobel Peace Prize.”
Ehud Barak : “I believes the prize will strengthen President Barack Obama’s capability to contribute to regional peace in the Middle East, and to an agreement between us and the Palestinians that will bring security, growth and prosperity to all the nations in the region.”