Genetic diversity and connectivity are key factors in determining a population’s resilience to future disturbance. This is especially relevant to corals, which are in global decline due to increasing frequency and strength of thermal anomalies and severe tropical cyclones. While many studies have investigated genetic diversity and population structure in corals, they focused on species being removed at the greatest rate from coral reefs, Acroporids and Pocilloporids, and it is unclear whether the patterns observed in these species reflects those found in more resilient species. Here, we use microsatellite markers and two lagrangian models with differing resolutions, to investigate population structure in a stress-tolerant coral survivor Cyphastrea microphthalma, Family Merulinidae, along the north-western Australian coastline. We found evidence of four genetic clusters with some level of admixture among them. However, while there was evidence of population structure within the intensively sampled Pilbara region, the patterns of connectivity differed to those reported previously. WA populations of C. microphthalma were also characterised by lower levels of genetic diversity at higher latitudes. High- and moderate-resolution lagrangian models did not significantly predict regional-scale genetic connectivity across the Pilbara and Ningaloo (500 km). Although the high-resolution model explained an order of magnitude more genetic variation, suggesting model resolution and resolving coastal processes are important. Over broad spatial scales (nearly 2000 km), all moderate-resolution model particle release durations significantly predicted the genetic differentiation, although over water distance best predicted genetic distance across this spatial scale. This study improves the understanding of connectivity in this region by focusing on a stress tolerant species incorporating a spatially more intensive sampling effort than previous coral studies. It also shows that further development of lagrangian models is required, such as inclusion of multi-generational stepwise models and larval behaviour, to improve predictions of connectivity for this coral species in this region.