Cồn Cỏ (listenⓘ ; also known as Tigris Insula in the maritime terminology) is an island district of Quảng Trị province in the North Central Coast region of Vietnam.

Although its name Cồn Cỏ means "the grass bund", but actually it originates from a wrong way of Hòn Hổ[3] (Tigris Insula), what is the Annamese translation of Palao Harimao in Middle Ages Champa language.

By recent archaeological work, in the Bến Nghè area of the island, there are rock artefacts believed to date to the Stone Age, tens of thousands of years ago.

According to local legends, the last Cham residents left the island in the 18th century to yield Kinh groups settling down.

According to the orientation of the Provincial People's Committee, what was proposed in an interdisciplinary meeting in November 2024, Cồn Cỏ and the surrounding waters will be a key economic zone (mô hình kinh tế trọng điểm) of the whole Quảng Trị in the period from 2025 to 2035.

[7][8][9] Also according to this resolution, the future of the inhabitants on the island must face a challenge : Both they want to develop a multi-service economy and to protect the ecological environment.

Cồn Cỏ Island has an area of 2.3 km2 (0.89 sq mi), the isometric form of hills, the highest peak of 63m.

Tourists are taken to the island to attend the memorial service for those who are still alive (lễ truy-điệu sống),[14] a custom that is thought to have been existed for a long time.