Biological data on life-history, such as age and growth, underpin fishery regulations and population models of harvested animals. Turbo militaris is a large Australian turbinid gastropod harvested for its high-quality meat by recreational and commercial fishers, and is an important resource for coastal First Nations Australians. Life-history studies on T. militaris are scarce, with no data on age and growth. Here, mark-recapture surveys were used at geographically distant locations in NSW to assess the growth rate of T. militaris and develop age and growth models for temperate and subtropical populations. Turbo militaris grew rapidly and reached maturity at a relatively small size; however, growth varied between populations of differing latitudes. Animals from the temperate population grew faster and attained a larger average maximum size than the subtropical population. Thus, the subtropical population were predicted to live longer and reach both maturity and legal harvesting size at an older age than the temperate population. Latitudinal variation in biological parameters raises concerns about effective management over spatial scales, especially for species with narrow endemic ranges, such as T. militaris. This research will provide indications of the suitability of current management regulations and guide future decision-making for T. militaris across its range.