Porcellio laevis (commonly called the swift woodlouse, or smooth slater in Australia) is a species of woodlouse in the genus Porcellio. It has a cosmopolitan distribution, and has been introduced to Australia, including Norfolk Island and Lord Howe Island. As the species epithet laevis as well as the vernacular name "swift woodlouse" suggests, the species is capable of quick bursts of speed when provoked. It occurs under rocks and fallen logs in damp areas, and is otherwise rarely encountered.