The Cook Islands Christian Church is a Christian Congregationalist church and has approximately 18,000 members including 56% of the residents of the Cook Islands.

The Cook Islands Christian Church played a major role in the expansion of Christianity in the Pacific in the 19^th and early 20^th centuries.  From the late 1830s missionaries went out to Samoa, New Caledonia, Vanuatu and PNG, among other places.

In recent times, the Cook Islands have experienced radical change.  Tourism has had a big impact on Cook Island life, especially on the main island of Rarotonga.  The other significant change has been the large scale migration of Cook Islanders to New Zealand and Australia.  Today there are only about 19,000 Cook Islanders remaining in the Islands, with about 50,000 in New Zealand and about 20,000 in Australia.  This has left many outlying islands depopulated, some having less than a third of the population they had 20 years ago.

A major challenge to the Church is the impact of global culture on the life and culture of the Cook Islands.  This has led to many social problems.