The icterine warbler (Hippolais icterina) is an Old World warbler in the tree warbler genus Hippolais. It breeds in mainland Europe except the southwest, where it is replaced by its western counterpart, melodious warbler. It is migratory, wintering in sub-Saharan Africa. The term icterine refers to its yellowish colouration.
This is a medium-sized warbler, 12–13.5 cm in length, similar to melodious warbler. The adult has a plain greenish-brown back with a paler wing panel, and yellowish underparts. The bill is slightly orange, strong and pointed, and the legs blue-grey. The sexes are identical, as with most warblers, but young birds are paler on the belly.
The song is a fast nasal babbling incorporating mimicry of other species. The call is described as teck or tec, tec, tec.
It is colloquially referred to by birders as icky.