Amager, located in the Øresund, is Denmark's most densely populated island, with more than 216,000 inhabitants. The protected natural area of Naturpark Amager makes up more than one-third of the island's total area of 96 km2.

Zealand at 7,031 km2 is the largest and most populous island in Denmark proper. Zealand had a population of 2,319,705 on 1 January 2020, comprising 40% of the country's population.