Cuba is the largest island in the Caribbean Sea (110,860 square kilometers or 42,803 square miles). It covers an area slightly smaller than Pennsylvania and is also the island with the largest single-nation population: estimated to be 11,047,251 in July 2014 by World Factbook.
The second-largest island is Hispaniola, where the countries of Haiti and Dominican Republic are located. It is significantly smaller in area than Cuba (76,420 square kilometers or 29,506 square miles). The combined population of these two countries is over 20 million, which is twice the population in Cuba, making Hispaniola the Caribbean island with the largest total population.