Mpigi District is bordered by Wakiso to the north and east, Kalangala to the south, to the southwest, Butambala to the west and Mityana to the northwest. The town of Mpigi, where the district headquarters are located, lies approximately 37 kilometres (23 mi), by road, west of Kampala.. In the 1970s Mpigi comprised the Buganda Kingdom counties of Kyaddondo, Busiro, Mawokota, Butambala and Gomba.
During the 1990s, Kyaddondo and Busiro were peeled off to form Wakiso. In 2010, Gomba was split off to form Gomba and Butambala became .Butambala Mawokota remained as the sole constituent of Mpigi district.
In 1991, the district population was estimated at about 157,400. The next census in 2002 estimated the population of the district at about 187,800, with an annual growth rate of 1.4%. In 2012, the population of Mpigi district was estimated at approximately 215,500. The district is primarily a rural district, with only 8.4% of the population living in urban areas.
Mpigi is one of the few areas in Uganda and likely the whole of Africa to have Humanist schools. The Uganda Humanist Schools Trust UHST sponsors 3 Humanist schools with the support of the International Humanist Ethical Union.
The major economic activity in Mpigi District is agriculture.
