East Siang is an administrative district in the state of Arunachal Pradesh in India.

In 1989 territory was transferred from West Siang district to East Siang. A decade later, in 1999, the district was bifurcated to make Upper Siang district.

According to the 2011 census East Siang district has a population of 99,019,roughly equal to the nation of Kiribati.This gives it a ranking of 615th in India (out of a total of 640).The district has a population density of 27 inhabitants per square kilometre (70/sq mi) .Its population growth rate over the decade 2001–2011 was 13.3%. East Siang has a sex ratio of 962 females for every 1000 males,and a literacy rate of 73.54%.

Various tribal groups of the Adi people live in various parts of the district. The local people traditionally follow Donyi-Polo, although a sizeable minority have converted to Christianity.

Languages spoken include Adi, a Sino-Tibetan tongue with approximately 140 000 speakers, written in both the Tibetan and Latin scripts; and Galo, an endangered language with 30 000 speakers, also in the Sino-Tibetan language family.

In 1978 East Siang district became home to the D’Ering Memorial (Lali) Wildlife Sanctuary, which has an area of 190 km2 (73.4 sq mi)