Egernsund is a small town, with a population of 1,437, in Sønderborg Municipality, Region of Southern Denmark in Denmark. Egernsund is situated on the northwestern end of the small peninsula of Broager Land on the northern shore of Flensborg Fjord and east of the short and narrow strait, called Egern Strait, connecting the firth with the small inlet of Nybøl Nor to the north. The Egernsund Bridge connects Egernsund with Alnor, the southern part of Gråsten, by crossing Egern Strait.