Karimunjava or Karimun Java is an archipelago of 27 islands in the Java Sea, Indonesia, approximately 80 kilometres northwest of Jepara and about 120 km from Semarang. They have a total land area of 78 km2. The main island is known as Karimun (2,700 ha), while the second-largest island is Kemujan (1,400 ha).

In 2011, the population of the island group was about 9,000 who lived on five of the islands. The population is largely Javanese, with pockets of Bugis and Madurese inhabitants. Javanese culture is dominant in the islands which are the only islands of Java where Javanese is the lingua franca.

Twenty-two of the islands have been declared 2001 as a marine reserve, the Karimunjava National Park. Five more islands are either privately owned or are under the control of the Indonesian Navy.