2. CAPITAL CITY THE CAPITAL OF SINGAPORE IS THE CITY OF SINGAPORE.As a city-state, Singapore is both the country and itscapital. Singapore Island is the main island ofSingapore, which is also called Pulau Ujong. This island isthe largest island of Singapore as well as the mostpopulous, with a population of over 5 million. SingaporeIsland has an area of about 710 square kilometers.