Polydora hoplura is a marine shell-boring spionid polychaete. It is native to Europe where it extends from southern England to the Mediterranean. Introduced populations are known from around the globe, including the Canary Islands, South Africa, Australia, New Zealand, Chile, Brazil, Japan, and California. It bores into calcareous substrates, usually the shells of mollusks, but also barnacles, coralline algae, sponges, and limestone. In some introduced locations it has had negative economic impacts by decreasing the condition and survival of shellfish in aquaculture. It can be especially abundant in cultivated oyster beds and onshore culture tanks for oysters and abalones.