The Cetti's Warbler (pronounced /?t??tiz/) (Cettia cetti) is an Old World warbler which breeds in southern Europe, and east southern temperate Asia as far as Afghanistan. It also breeds in northwest Africa. It is the only bush warbler which occurs outside Asia. It is a recent colonist to southern England and Wales, with first breeding records for the UK in 1973.

This small passerine bird is mainly resident in Europe, but eastern populations migrate short distances, wintering within the breeding range.

This is a bird of dense vegetation, usually close to water. A reedbed with bushes would be a typical site. The nest is built in a bush near water, and 3-6 eggs are laid.

This is a medium-sized warbler, 13-14cm long. The adult has a plain brown back, whitish grey underparts, a broad tail and short wings. Structurally, it resembles an oversized Wren. The sexes are identical, as with most warblers. Like most warblers, it is insectivorous.

This is a skulky species which is very difficult to see. It has the to apparent ability to move from one bush to another without crossing the intervening space, reflecting the tendency of this bird to creep through the low foliage.

Males are often only detected by the loud song, which has an explosive plit, followed by the rhythm What's my name, Cetti-Cetti-Cetti, that's it. The female is nearly impossible to find, since she does not sing.

This bird is named after the Italian zoologist Francesco Cetti.