The seasonally adjusted Live Register figure rose by 3,300 in December to stand at 426,700 from November's total of 423,400.
The figure had fallen in October for the first time since March 2007.
The CSO says there was an unadjusted increase in the Live Register of 46.1% in 2009. This compares with an increase of 70.2% in 2008.
The unemployment rate was unchanged at 12.5%, the CSO added.
