North Sentinel Island is one of the Andaman Islands, an Indian archipelago in the Bay of Bengal which also includes South Sentinel Island. The island is a protected area of India. It is home to the Sentinelese, an indigenous tribe in voluntary isolation who have defended, often by force, their protected isolation from the outside world. The island is about 8 kilometres (5.0 mi) long and 7 kilometres (4.3 mi) wide, and its area is approximately 60 square kilometres (23 sq mi).

John Allen Chau was an American evangelical Christian missionary who was killed by the Sentinelese, a tribe in voluntary isolation, after illegally traveling to North Sentinel Island in an attempt to introduce the tribe to Christianity.