Thyreus nitidulus, commonly known as the neon cuckoo bee, is a parasitic bee of the genus Thyreus, called cuckoo bees. It is a stocky bee, notable for its brilliant metallic blue- and black-banded colors. Originally described by Danish entomologist Johan Christian Fabricius in 1804 as Melecta nitidula – from a collection in the Aru Islands or northern Australia – it was given its current scientific name Thyreus nitidulus in 1959 by M. A. Lieftinck. The specific epithet is derived from the diminutive of the Latin adjective nitidus "shining" (i.e. "a little shiny").