This radical new textbook provides readers with a balanced, research-focused, critical understanding of health psychology through an inclusive lens, addressing issues relating to diversity, inclusion and decolonisation of the curriculum. In so doing, it offers a new understanding on established topics in the field of health psychology to create a more comprehensive and nuanced understanding of health and illness that reflects the diversity of human experience. The book explores the importance of biopsychosocial processes in health and illness, through an exploration of socio-cultural factors beyond the restrictive Western-centric models of health to include Indigenous populations and marginalised groups. Within this book, readers are introduced to the negative health impacts of direct and transgenerational colonialism, racism, restrictions on cultural practices, freedoms and institutionalisation. This includes recognising the impact of systemic oppression on health outcomes and advocating for policies that address health disparities of diverse populations in order to tailor interventions to meet their specific needs. Research studies present examples of how sexual orientation, gender identity, ethnicity, culture and disabilities intersect with health outcomes in the exploration and the perpetuation of health disparities. Primarily written for undergraduates, the book also provides a firm foundation for graduate students, teachers and practitioners in psychology, nursing and the allied health professions.