Leaf-warblers are small insectivorous birds formerly placed in the "Old World warbler family, but now moved into the new family Phylloscopidae. There are presently some 76 species in the family.

Its members occur in Eurasia, ranging into Wallacea and Africa (and the Arctic Warbler breeding east into Alaska). Most live in forest and scrub and frequently catch food on the wing. The species are of various sizes, often green-plumaged above and yellow below, or more subdued with greyish-green to greyish-brown colours, varying little or not at all with the seasons.