Synanthedon flaviventris, the sallow clearwing, is a moth of the Sesiidae family. It is found in most of Europe (except Ireland, Norway, the Netherlands, the Iberian Peninsula, most of the Balkan Peninsula and Ukraine) and Russia (southern Siberia, Baikal, Irkutsk, Chaborowsk, Ussuri). The wingspan is 17–20 mm. Adults are on wing from June to July. The species has a two-year life cycle, with adults present mostly in even years.