The jobless rate rose for a third consecutive month to hit the highest level in more than five years, the monthly report from the State Secretariat for Economic Affairs (Seco) showed.
The rate was well above the 3.4 percent recorded in December 2014 and marked the highest level since April 2010.
The unemployment rate of foreigners climbed to 7.3 percent from 6.7 percent in November, while the level for Swiss citizens increased to 2.5 from 2.4 percent, Seco said.
The overall number of people registered as unemployed at regional job centres in December totalled 220,209, eight percent more than in the same month a year earlier.
The average jobless rate for 2015 was 3.3 percent, up slightly from 3.2 percent in 2014.
The canton of Neuchâtel recorded the highest rate in December at 6.1 percent, up from 5.5 percent, while the canton of Appenzell Innerrhoden had the lowest rate of one percent, an increase from 0.9 percent in November.
The canton of Zurich, Switzerland's largest job market, registered a rate of 3.9 percent, compared to 3.7 percent the previous month.
Last month, Seco said it expected average unemployment to increase for 2016 to 3.6 percent despite anticipated higher growth in the economy, which is forecast to expand by around 1.5 percent this year from 0.8 percent in 2015.
Economists have noted that the strong Swiss franc has hurt exporters from the country by making their products and services more expensive to foreign customers.