The Nicobar Islands are an island chain in the eastern Indian Ocean, and are part of India.

The Nicobar islands include 22 islands of various sizes, the largest being Great Nicobar. The total land area of the chain is 1841 km². The highest point on the Nicobars is Mount Thullier at 642 m. The population of the islands was 42,026 in 2001, roughly 65% of whom are indigenous peoples (the Nicobarese and Shompen peoples, listed among the Scheduled Tribes of India), and 35% migrants from India and Sri Lanka.

The Nicobars are located southeast of the Indian subcontinent, separated by the Bay of Bengal by about 1,300 km, and are separated from the Andaman Islands to the north by the 150 km wide Ten Degree Channel and are 189 km from the Indonesian island of Sumatra to the southeast. The Andaman and Nicobar Islands separate the Bay of Bengal from the Andaman Sea. Until the 2004 Indian Ocean earthquake, Indira Point, south of Great Nicobar, was the southernmost point in India.

The islands cluster into three groups. The northern group includes Car Nicobar (127 km²) and uninhabited Batti Malv (2 km²). The central group includes Chowra (8 km²), Teressa (101 km²), Poahat (13.3 km²), Katchal (174 km²), Camorta (188 km²), Nancowry (67 km²), and Trinket (86 km²); the Isle of Man and Tillangchong (17 km²) are uninhabited. Tillangchong is a wildlife sanctuary. The southern group includes Great Nicobar (1045 km²), Little Nicobar (157 km²), Kondul (4 km²) and Pulomilo (1 km²); the islets of Meroe, Trak, Treis, Menchal, Cubra, Pigeon, and Megapod are uninhabited. Megapod is a wildlife sanctuary.

Administratively the Islands are part of the Andaman and Nicobar Islands, a Union Territory of India. The capital of the Andaman and Nicobar Islands territory is Port Blair on South Andaman. The Union Territory is divided into two districts, Andaman district and Nicobar district (the latter encompassing all of the Nicobars). The Indian Government presently restricts access to the Nicobars by special permit, and in general non-Indian citizens are forbidden from visiting the Nicobar Islands.