Indonesia is a place.
Indonesia ( [ ɪndəˈniːʒə ] or [ ˌɪndoʊˈniːziə ] ; Indonesian : [ ɪndonesia ] ) , officially the Republic of Indonesia ( [ rɛpublik ɪndonesia ] ) , is a unitary sovereign state and transcontinental country located mainly in Southeast Asia with some territories in Oceania . Situated between the Indian and Pacific oceans , it is the world 's largest island country , with more than seventeen thousand islands . It has an estimated population of over 260 million people and is the world 's fourth most populous country , the most populous Austronesian nation , as well as the most populous Muslim-majority country . Its capital and country 's most populous city is Jakarta , which is also the most populous city in Southeast Asia and the second in Asia .