Amager ([ˈɑmɑːˀ] or, especially among older speakers, [ˈɑmæːɪ̯ˀɐ]) is a Danish island in the Øresund. The Danish capital, Copenhagen, is partly situated on Amager, which is connected to the much larger island of Zealand by five bridges.

Amager has long been populated, and well used, thanks to its rich soil and proximity to Copenhagen. In 1521, Christian II invited some Dutch farmers to move to Amager and grow vegetables to supply the Danish Court and Copenhagen. It was only in the late 19th century that Copenhagen began to expand onto the island (Sundbyerne), and in 1902 these built-up areas were incorporated into Copenhagen.

During the Second World War, high unemployment in Copenhagen led authorities to drain a large part of the sea, west of the island, and build a dam to hold out the water, effectively adding one half of Amager's previous area to the island.

The reclaimed area is currently known as Kalvebod Fælled, and was originally a military area, but today it is part of a major construction area called the Ørestad, being thought of as an extension to central Copenhagen. The area houses such major facilities as the Bella Center, a convention and exposition center, and Field's, the second-largest shopping center in Scandinavia. This project was initiated by the Danish government.