Martinssonia is an extinct genus of Cambrian arthropod from the Orsten Lagerstätte.

Martinssonia is a small (roughly 1.5 mm long) arthropod, with eight pairs of appendages and ten segments including the eyeless head.

It has a pair of antennae, twelve biramous appendages on its head and front two body segments and a final pair of uniramous appendages on its third segment.

[1] Martinssonia was presumably a benthic detritivore, stirring up food particles from the seafloor.

[1] Martinssonia is named for Anders Martinsson, a former Professor of Palaeobiology at Uppsala University in Sweden.