The streak-breasted bulbul or mottle-breasted bulbul (Hypsipetes siquijorensis) is a songbird species in the bulbul family (Pycnonotidae). It is one of the species of Ixos that now usually warrants inclusion in the genus Hypsipetes – as long as this is 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).