Sironko District is a district in the Eastern Region of Uganda. The district was created in 2000 and had previously been part of Mbale District. Sironko is the main commercial town in the district.

Sironko District is bordered by Bulambuli District to the north, Kapchorwa and Kween Districts to the north-east, Kenya to the east, Bududa District to the south-east, Mbale District to south-west, and Bukedea District to the west. Sironko lies 22 kilometres (14 mi) north-east of Mbale, the largest city in the Bugisu sub-region.

The Uganda Bureau of Statistics (UBOS) 2024 National Population and Housing Census final results, Sironko District consists of county, sub-counties including town councils, and parishes also including wards.

This is the sole administrative county, covering the entirety of Sironko District. It is also further divided into town councils and sub-counties.

In 1991, the national population census estimated the district population at 147,700. The 2002 census estimated the population at 185,800, with an annual growth rate of 2.6 percent. The population was estimated to be 239,600 in 2012. in 2014, 242,421 and 2024 the population was 298,363.

The district has a total area of 446.1 square kilometres (172.2 mi²).

Sironko is the largest town and the administrative headquarters of the district. Mafuni, Nakaloke, Mutufu, and Budadiri are the main trading centers within the district.

Budadiri County is the only county in the district.