Aesthetic value, or beauty, is important to the relationship between humans and natural environments and is, therefore, a fundamental socioeconomic attribute of conservation alongside other ecosystem services. However, beauty is difficult to quantify and is not estimated well using traditional approaches to monitoring coral reef aesthetics. To improve the estimation of ecosystem aesthetic values, we developed and implemented a novel framework used to quantify features of coral reef aesthetics based on people’s perceptions of beauty. Three observer groups with different experience to reef environments (Marine Scientist, Experienced Diver and Citizen) were virtually immersed in Australian’s Great Barrier Reef using 360-degree images. Perceptions of beauty and observations were used to assess the importance of eight potential attributes of reef aesthetic value. Among these, heterogeneity, defined by structural complexity and colour diversity, was positively associated with coral-reef aesthetic values. There were no group-level differences in the way the observer groups perceived reef aesthetics suggesting that past experiences with coral reefs do not necessarily influence the perception of beauty by the observer. The framework developed here provides a generic tool to help identify indicators of aesthetic value applicable to a wide variety of natural systems. The ability to estimate aesthetic values robustly adds an important dimension to the holistic conservation of the Great Barrier Reef, coral reefs worldwide, and other natural ecosystems.