Bull sharks (Carcharhinus leucas) are adaptable apex predators that rely on estuarine and riverine habitats as nurseries, yet how kinship and movement together structure their populations is poorly understood. We combined genome‑wide single‑nucleotide polymorphism (SNP) data with acoustic telemetry to investigate fine‑scale genetic structure, kinship, and spatial connectivity across four neighbouring Sunshine Coast river systems in southeast Queensland, Australia. Significant genetic differentiation among rivers indicates that nurseries function as distinct populations, with full‑ and half‑sibling relationships detected only within rivers and between‑river kinship limited to cousin‑level relationships, consistent with male‑mediated gene flow and strong female site fidelity. Acoustic tagging of >100 juvenile and sub‑adult bull sharks revealed overlapping habitat use, rainfall‑driven downstream movements of juveniles into turbid lower estuaries, and strong site attachment of sub‑adults to nearshore coastal waters – including repeated visits to neighbouring rivers and returns to home systems. Together, these results demonstrate that genetically distinct nurseries are ecologically connected by coastal movements, underscoring both the susceptibility of local populations to the loss of breeding females and the need to understand connectivity in a rapidly changing climate hotspot.