The Protestant Church in Indonesia is a Reformed church; it is a member of World Communion of Reformed Churches.
The Protestant Church in Indonesia was formed in Ambon, Maluku in 1605 under the name of the Protestant Church in the Netherlands Indies, in Dutch De Protestantsche Kerk in Nederlandsch-Indië. In 1619, the headquarters was moved to Batavia. The denomination inherited the missions left by the Portuguese. The church supported missions all over Indonesia. Its territories cover several areas like the Maluku Islands, Minahasa, Java, Sumatra, East Nusa Tenggara.
In the 1930s, the church spread rapidly. The church composed of 12 autonomous churches
In the 20th century, it adopted a more Presbyterian church order. It has 4,800 congregations and 3.1 million members.