Kutubdia Dwip () is an island of the Cox's Bazar District of Bangladesh. It is famous for lighthouse.
It is located in north part Cox's Bazar District.
Kutubdia Island reduced to half of It's original size in 20 years due to erosion. Since 1991, six villages on the island of fishermen and salt workers have been swamped as well as about 40,000 people have fled from their homeland.