Mesuji River is a river in Lampung province, Sumatra island, Indonesia, about 250 km northwest of the capital Jakarta.
The river flows in the southeast area of Sumatra, which has a predominantly tropical rainforest climate (designated as Af in the Köppen-Geiger climate classification). The annual average temperature in the area is 26 ðC. The warmest month is August, when the average temperature is around 28 ðC, and the coldest is May, at 25 ðC. The average annual rainfall is 3,248 mm. The wettest month being December, with an average of 547 mm rainfall, and the driest is September, with 40 mm of rain.