Kilsund is a village in the municipality of Arendal in Aust-Agder county, Norway. It is located on the island Tverrdalsøya. Its population (2009) is 729. The village is located just north of Flosta island. It is about 6.5 kilometres (4.0 mi) northeast of Strengereid, 10 kilometres (6.2 mi) northeast of Eydehavn, 16 kilometres (9.9 mi) northeast of the city of Arendal, and 8 kilometres (5.0 mi) south of the city of Tvedestrand.