According to the 2002 national census, the Busoga sub-region was home to an estimated 2.5 million people at that time. Namutumba District is divided into the following sub-counties and one town council:
In 1991, the national population census estimated the district population at about 123,900. The national census in 2002 estimated the population of the district at about 167,700. The annual population growth rate in the district was calculated at 2.7%. It is estimated that the population of Namutumba District in 2012 was approximately 218,900. The table below depicts the population growth in the district between 2002 and 2012. All figures are estimates.