A new barnacle species, Chthamalus neglectus Yan and Chan, 2004, was described from Hong Kong. It belongs to the “challengeri” group of Chthamalidae. The larvae of Chthamalus neglectus differ from C. challengeri, C. antennatus, C. montagui, and C. dalli (challengeri group) in the teeth of the labrum, shape of cephalic shield, setation formula, and cephalic shield sculpturing under both light and scanning electron microscopes. This further confirms it is a new Chthamalus species.