River in Aileu
Map of East Timor highlighting Aileu District
|Subdistricts||Aileu, Laulara, Lequidoe, Remexio|
|• Total||737 km2 (285 sq mi)|
|• Density||66/km2 (170/sq mi)|
|• Density rank||8th|
|• Total||7,745 (as of 2004)|
|ISO 3166 code||TL-AL|
Aileu is an administrative district of East Timor. Aileu Municipality has a population of 48,554 (Census 2015) and an area of 737 km². The capital of the district is also named Aileu. The subdistricts are Aileu Vila, Laulara, Lequidoe and Remexio.
Aileu is in the northwestern part of East Timor and is one of only two landlocked districts, the other being Ermera. It borders Dili to the north, Manatuto to the east, Manufahi to the southeast, Ainaro to the south, Ermera to the west, and Liquiçá to the northwest. It was formerly part of the district of Dili but was split in the final years of Portuguese administration.
As part of the Timor-Leste Government decentralization program the former District of Aileu is now organised as the Municipality of Aileu, headed by a Municipal Administrator. The four subdistricts are now organised as Administrative Posts. Aileu is the focus of several development programmes from NGOs, including WaterAid, World Vision and Plan International. In May 2000 the Hume City Council and Moreland City Council and the communities in Melbourne Australia, established a friendship relationship with the Aileu Distrist, called "Friends of Aileu". The friendship relationship has been renewed periodically, with the signing of updated Friendship Agreements in 2005, 2010 and 2016. and 
- Aileu Vila Subdistrict (place of capital)
- Laulara Subdistrict
- Lequidoe Subdistrict
- Remexio Subdistrict