This interactive, open-access textbook provides a comprehensive and engaging exploration of the challenges and opportunities facing our oceans, with a strong Australian focus and global relevance. It integrates ocean science, sustainability, policy and community perspectives to build ocean literacy and support the development of a sustainable Blue Economy. Drawing on contemporary research, international and national frameworks (including the UN Sustainable Development Goals, the UN Decade of Ocean Science and Australian marine strategies), the textbook examines key themes such as climate change and ocean solutions, food security, biodiversity conservation, cleaner oceans, coastal resilience, ocean equity and Indigenous empowerment. Rich multimedia content, including interactive activities, videos and podcasts, are embedded throughout to support active learning and real-world application. Designed for students, educators, practitioners and the broader community, this resource bridges science, policy and practice to inform decision-making and foster collective stewardship of Australia’s marine environment.