Pervasive population irruptions of coral-eating crown-of-thorns starfish (COTS) are a major contributor to sustained coral loss and reef degradation. The incidence and spread of such population irruptions inherently rely on spatiotemporal variability in settlement and recruitment success. Given the lack of gregarious settlement in COTS, the presence of coralline algal cues signaling suitable habitat appears critical to their recruitment patterns and population dynamics. This presentation outlines recent advances in our efforts to resolve persistent knowledge gaps surrounding the induction and patterns of COTS settlement. Laboratory bioassays demonstrated substantial variation in COTS settlement response to cues associated with 15 coralline algal species. The coralline alga Melyvonnea cf. madagascariensis induced by far the highest settlement rates (> 90%/ 98% at 24h/ 48h), while Lithophyllum cf. kotchyanum and two Porolithon spp. induced very little settlement (< 2%/ 10% at 24h/ 48h). Such clear preference for particular coralline algae has important ecological implications because settlement in adverse environments and/or delays in settlement negatively impact recruitment success. The distribution and abundance of highly inductive settlement cues associated with coralline algal species may thus be an underappreciated factor in explaining COTS population replenishment and the striking spatial differences in adult densities across Australia’s Great Barrier Reef.