What is the world's most densely populated island?Indonesia's island of Java is the large island that is most densely populated with a population density of 2,100 people per square mile (810 per square kilometer). Java is home to more than 107 million people and is 51,000 square miles (132,089 km2). The islands of Manhattan, Hong Kong, and Sinapore are three other highly densely populated islands.
However, the tiny island of Santa Cruz del Islote, Colombia is said to be the most densely populated with a population of over 1200 in 0.003 square miles (0.01 km2).
Wikipedia provides an incomplete list of densely populated islands.
See a listing of the World's Largest Islands here on my site.