Ashmore and Cartier Islands is a group of uninhabited islands and reefs located in the Indian Ocean off the northwest coast of Australia. The islands are part of the territory of Australia, but are not considered to be part of any state or territory within Australia.

The Ashmore Reef National Nature Reserve covers both Ashmore Reef and Cartier Island, and was established in 1983 to protect the unique marine environment surrounding the islands. The area is home to a diverse array of marine life, including over 250 species of coral and more than 500 species of fish. The islands are also an important nesting site for sea turtles and seabirds.

Due to their remote location and protected status, the islands are not open to the public for tourism or other activities. However, research and scientific expeditions are permitted with prior approval from the Australian government.

The islands have a rich cultural history, with evidence of human occupation dating back over 4,000 years. The islands were visited by European explorers in the 17th century, and were used as a base for guano mining and fishing in the 19th and early 20th centuries. During World War II, the islands were used as a base for Australian and Allied military operations in the region.