87% of East Kalimantan's population was Muslim in June 2021.

The Directorate General of Population and Civil Registration (Dukcapil) of the Ministry of Home Affairs (Kemendagri) recorded that the population of East Kalimantan was 3.8 million in June 2021. Of this number, 3.32 million people, or 87.41%, are Muslim.

East Kalimantan's Christian population numbered 286,150 (7.52%). 168,140 residents in the province are Catholic.

Furthermore, 15,630 (0.41%) of East Kalimantan's population are Buddhist. 8,500 (0.22%) are Hindu.

352 people (0.01%) adhere to Confucianism, while 308 (0.01%) follow indigenous beliefs.

By gender, 1.97 million (51.88%) of East Kalimantan's population are male. Meanwhile, 1.83 million (48.12%) are female.

Based on marital status, 1.87 million (49.17%) are unmarried. 1.76 million (46.21%) are married.

There are also 112,930 (2.97%) widowed individuals. The number of divorced individuals is 62,940 (1.65%).

East Kalimantan is a province with an area of 129,066 square kilometers (km) and a population density of 29 people/km². Administratively, East Kalimantan is divided into 7 regencies and 3 cities, comprising 103 districts, 841 villages, and 197 urban villages.