The sulphur-bellied bulbul (Ixos palawanensis) is a songbird species in the bulbul family (Pycnonotidae). Past studies have argued the species might warrant inclusion in the genus Hypsipetes – as long as this was kept separate from Ixos – as it may be a close relative of the Philippine bulbul (H. philippinensis), which in turn is closely related to the type species of Hypsipetes, the black bulbul (H. leucocephalus)., however current taxonomic consensus places it in the genus Iole.