DiCaprio bought Blackadore Caye, 104 acres of wild, unpopulated land off the coast of Belize, with a partner soon after he set foot in the country a decade ago, reported the New York Times.
Now, the actor has joined a developer to create an eco-conscious resort there, which will open in 2018.
Blackadore Caye has suffered from overfishing, an eroding coastline and the deforestation of its mangrove trees but DiCaprio and his partner plan to refurbish its natural resources.
"The main focus is to do something that will change the world. I couldn't have gone to Belize and built on an island and done something like this, if it weren't for the idea that it could be groundbreaking in the environmental movement," DiCaprio told the newspaper.