Globally, Indigenous knowledge systems, people, and Country are increasingly being recognised in marine spatial planning. Indigenous coastal communities, on the east coast of Australia, are actively protecting the cultural and ecological values of their ancestral estates and related management practices. Yet, in Australia, codesigned marine spatial planning with Indigenous Peoples, is still in its infancy. In collaboration with the Gamay Rangers, Sydney, we combined Indigenous Science and Western Science to develop a new cross-cultural approach to Marine Protected Area design in an urban setting. A combination of ecological, heritage, and government, along with semi-structured interviews to elicit Indigenous Science, was used to produce a portfolio of Marine Protected Area Marxan scenarios. The scenarios showed that in the absence of Indigenous Science, existing areas protected as National Parks and reserves were selected. When Indigenous Science was included, areas of high cultural value, such as fishing places, burial sites, and dreaming and ceremonial sites were prioritised. Therefore, this comparative marine spatial planning study showed that including Indigenous Science can alter optimal planning scenarios that shift conservation priorities from classical Western values towards Indigenous values which is becoming an increasing focus in conservation planning globally. This presentation will cover the background and intersection of marine spatial planning and Indigenous Peoples, the methodological framework, the results, and how the results contribute to the Symposium by showcasing a novel foundational approach that can bringing together western values and Indigenous values that work toward co-designed Marine Protected Areas.