Kouilou (Kongo: Kwilu, Kuilu ) is a department of the Republic of the Congo. Covering the country's coastline, it has an area of 13,650 square kilometres and at the start of 2023 it was home to about 97,362 people. The department borders Niari Department, the commune of Pointe-Noire, and internationally, Gabon and the Cabinda area of Angola.

Since 2011 the town of Loango has been the capital of the Kouilou department. Before, the capital was Hinda (see "Villages and towns" part).

Kouilou is also the name of a river, the Kouilou-Niari River.

Administrative divisions

Kouilou Department is divided into six districts:

Districts

1. Hinda District
2. Madingo-Kayes District
3. Mvouti District
4. Kakamoeka District
5. Nzambi District
6. Loango District

Villages and towns

• Hinda (old capital of the department until 2011)
• Madingo-Kayes
• Mvouti.