The Purchasing Managers’ Index (PMI) for the manufacturing sector came in at 49.6 for December, a drop of almost two points from 51.8 in the previous month. It was also the lowest reading since February 2013.
The drop was due to a contraction in new orders and slower growth in export orders.
Meanwhile, the corresponding index for the electronics sector posted its 23rd straight month of expansion, coming in at 50.5. It was a marginal dip from the previous month's reading of 50.6.
A reading above 50 indicates that the manufacturing sector is generally expanding, while a reading below 50 suggests contraction.
The lacklustre performance is in line with weakness seen throughout the region.
Economists said this points to a slow start to 2015. However, some expect activity to pick up, due to demand growth from developed economies.
Mr Jeff Ng, an economist at Standard Chartered Bank, noted: "In terms of Singapore, the manufacturing sector continues to support the economy. We will continue to see that going forward into this year.
“The key risk is that there is still going to be a lot of volatility in the short term at least for the first half of the year. With the overall economic growth not improving on a linear path, we should see growth for Singapore on a quarter-to-quarter and even a month-to-month basis being very volatile. But I think overall, throughout the course of the year, we should see some pick-up."