Mwandiga is an administrative ward located in the Kigoma District of the Kigoma Region in Tanzania. The area covers a total land size of 40.5 km² (15.6 sq mi) and sits at an average elevation of 860 meters (2,820 ft).
According to data from the Tanzania National Bureau of Statistics, the population of the ward grew significantly over a four-year period. In 2016, the population was recorded at 20,810 people, an increase from the 18,906 residents reported in 2012.