His job approval was 49.1 percent, the third-lowest of post World War II presidents and similar to Bill Clinton's, the Gallup Poll said in a report released Monday.
Obama tied with Harry Truman as having the lowest ratings of any president who was re-elected, Gallup said.
His approval figures rose to 48.1 percent in his fourth year in office after the death of Osama bin Laden, from a 44.4 percent average in his third year.
During the last three months of his first term, he rated 51.9 percent approval. That's the same approval his predecessor George W. Bush had in the last quarter of his first term.
The report noted: "As in the latter part of his first term, the president's ability to succeed in these efforts will depend greatly on his ability to work with a divided Congress. The extent to which he can do that, along with the health of the economy, will be major factors in determining the level of public support Obama will get in his second term in office."