The Norwegian Refugee Council's report also found that 3.5 people have been displaced since the start of this year, a statement from the Office of the United Nations High Commissioner for Refugees said.
The study, conducted by NRC's Geneva-based Internal Displacement Monitoring Centre, said about 830,000 of those displaced last year fled their homes because of the Arab Spring.
"While the Arab Spring uprisings caused significant surges in internal displacement," said Kate Halff, head of IDMC, "events in other regions, such as the spread of the armed conflict in Afghanistan and the activities of drug cartels and paramilitary gangs in Colombia, all added to this figure, while famine and conflict added to the already extreme vulnerabilities of millions of displaced people in Somalia."
Many countries where armed conflict had ended in 2011 remained unstable and people continued to be forced to flee from their homes, the report found.
In Africa, the number of internally displaced people dropped from 11.1 million in 2010 to 9.7 million in 2011, the report said, with many of those displaced returning to their homes, mostly in the Ivory Coast, Chad and Uganda.
"What the past has told us is that they, alongside the millions newly displaced across the world in 2011, face similar risks of protracted and even repeated displacement if governments, and their international partners, cannot ensure a stable environment for them," Halff said.
Pistorius testifies he didn't consciously pull trigger when he shot girlfriend
'Happy' fan videos make Pharrell cry [VIDEO]