The willie wagtail, scientific name Rhipidura leucophrys, is a passerine bird native to Australia, New Guinea, the Solomon Islands, the Bismarck Archipelago, and Eastern Indonesia. It is a common and familiar bird throughout much of its range, living in most habitats apart from thick forest. Measuring 19–21.5 cm in length, the willie wagtail is contrastingly coloured with almost entirely black upperparts and white underparts; the male and female have similar plumage.

Wagtails are a group of passerine birds that form the genus Motacilla in the family Motacillidae. The common name and genus name are derived from their characteristic tail pumping behaviour. Together with the pipits and longclaws they form the family Motacillidae.