Galathea nexa is a species of squat lobster in the family Galatheidae.
G. nexa males grow up to , while the females are up to . The first pair of legs have distinctive spikes on the second joint. It is reddish-green with some darker spots.
G. nexa is sometimes found in the subtidal zone, but is usually found deeper than in the seawater.
It is found in all European seas, from Norway to Great Britain and Ireland to the Mediterranean.
It is fished and sold in some areas; in Belgium it is called or .