Vendelsöarna ("Vendelsö islands") is an archipelago and a nature reserve in Varberg Municipality, Sweden, near the border with Kungsbacka Municipality. The reserve consists of the northern part of the main island Vendelsö and the surrounding islands Brattö, Norstön, Kidholmen, and Älmö. There are two other islands in the archipelago, Ustö and Knarrskär, but they are not included in the reserve. The protected area has an area of 563 hectares, of which 128 hectares are land.