Marine turtles have been used as ecological health proxies for decades due to their high site fidelity and longevity. As a result, many studies have used marine turtles to explore the effects of anthropogenic impacts on the marine environment. Establishing a standardised range of metrics that reflect the condition of wild marine turtle populations allow researchers to examine the impacts of various threats and environmental variations. This study presents baseline health parameters for two island foraging green turtle populations on the southern Great Barrier Reef, Queensland, Australia. It was hypothesised that parameter ranges would differ between sites due to variation in environmental conditions, food availability, and proximity to land based pollutants. Using a portable blood analyser and standard veterinary laboratory analysis, ranges for various haematology, blood gas and biochemical parameters were calculated. Using a standardised ratio of weight (kg) to curved carapace length (cm), a scaled mass index model was calculated for these two populations for use as a standardised measurement for body condition. While overall body condition did not differ between the islands, mean amylase, cholesterol, base excess, bicarbonate, and total carbon dioxide values were significantly higher at Lady Elliot Island. Annual monitoring and sampling of these populations is required to disentangle naturally occurring spatial and temporal variation of these ranges with external drivers. The results of this study provide standardised baseline health ranges, therefore health changes in response to environmental and anthropogenic pressures can accurately be assessed in the future.