Dellen is a lake system in the province of Hälsingland, Sweden.

Southern Dellen has a surface area of 52 km2 and a water volume of 1,226 million m3.

Northern Dellen has an area of 82 km2 and a water volume of 1,489 million m3.

The resulting impact crater measures about 19 kilometers in diameter.

An installation of the Sweden Solar System representing Pluto and Charon lies near the southern lake; the pillars holding the model objects are made of dellenite.