Køge Bugt or Køge Bay is an approximately 500 km2 shallow Danish bay in the southern part of Øresund, between Greater Copenhagen area in the North (or more precisely the southernmost peak of Amager) and Stevns Klint in the South, and as a part of Zealand. It's labeled after the Danish town Køge, which is located towards its southern part. The area around the bay's shores are built-up from Copenhagen to Køge, including Copenhagen suburban areas like Brøndby Strand, Vallensbæk, Ishøj, Hundige, Jersie and others. The seafloor is not located deeper than 10 meters anywhere inside the bay. Due to its closeness to the Baltic Sea, the average surface salinity is lower than elsewhere in Øresund, especially when compared to the northern parts of this sound.
In 1427 a Kalmar Union fleet was resoundingly victorious in a sea battle against the Hanseatic League. 1 July 1677, a sea battle between a Dano-Norwegian and a slightly larger Swedish fleet occurred in the bay. The outcome was a Dano-Norwegian victory, lead by Admiral Niels Juel. Another battle between a Dano-Norwegian fleet and Sweden was fought in 1710.