The rise followed a 5.0% decrease in November.
Economists had expected a 0.3% increase according to the median of 7 estimates.
On a seasonally adjusted month-on-month basis, exports rose 6.6% in December, extending the prior month's 3.7% expansion, Enterprise Singapore said in a statement.
Economists had forecast a 3.6% rise.
(Reporting by Aradhana Aravindan in Singapore; Editing by Himani Sarkar)