Darwin is the capital city of the Northern Territory, Australia. The city has nearly 53% of the Northern Territory's population, with 139,902 at the …Darwin is the capital city of the Northern Territory, Australia. The city has nearly 53% of the Northern Territory's population, with 139,902 at the 2021 census. It is the smallest, wettest, and most northerly of the Australian capital cities and serves as the Top End's regional centre.