It is native to the northeastern Atlantic Ocean where it inhabits shallow water areas of sand, mud and stones.

[2] This worm can be confused with other species, particularly the closely related Phyllodoce mucosa, so its precise range is unclear; it is present in the Arctic and North Atlantic Oceans, the Skagerrak and Kattegat, the western Baltic Sea, the North Sea and the English Channel.

Its depth range is from the intertidal zone down to about 400 m (1,300 ft), and it is found on sand, muddy-sand, shelly gravel and rock bottoms.

[2] Phyllodoce maculata is a predator and scavenger, feeding on invertebrate prey and the bodies of small dead animals.

During breeding, several males may sometimes be seen swarming around a female on the sediment surface, and the greenish, gelatinous egg masses produced are attached to stones or other underwater objects.