Millipedes (originating from the Latin mille, “thousand”, and pes, “foot”) are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments. Each double-legged segment is a result of two single segments fused together. Most millipedes have very elongated cylindrical or flattened bodies with more than 20 segments, while pill millipedes are shorter and can roll into a tight ball. Although the name “millipede” derives from Latin for “thousand feet”, no species was known to have 1,000 or more until the discovery in 2020 of Eumillipes persephone, which can have over 1,300 legs.

Most millipedes are slow-moving detritivores, eating decaying leaves and other dead plant matter; however, some eat fungi or drink plant fluid. Millipedes are generally harmless to humans, although some can become household or garden pests.