Decapod crustaceans are a diverse group of invertebrates, which underpin global aquaculture and fishing industries. Yet they are routinely underrepresented in animal welfare debates, science, and law. In this chapter, we discuss pain and welfare considerations for decapod crustaceans. We summarise the scientific evidence for pain in decapods and advocate a precautionary approach, which means that we should consider their welfare. We outline how humans use decapods and highlight potential welfare challenges in aquaculture and fisheries, emphasising the many knowledge gaps. For vets, we suggest a health inspection procedure and introduce key welfare indicators. We finish by describing relevant legislation and industry standards. We hope this chapter advances the emerging science of decapod pain and welfare.