Langøy is an island in Kragerø Municipality in Telemark county, Norway.

Its name, which means "Long island", reflects its shape only to some extent.

The island is populated, and there is a ferry, operated by Kragerø Fjordbåtselskap, connecting the island to the town of Kragerø.

With the decline of ironworks in Norway in the 1860s, there was soon no market for iron, and the last of the mines at Langøy had to shut down in 1869.

This Telemark location article is a stub.