Design has been a massive failure. It has functioned in the service of industry and capitalism, leaving us a world with several crises which we are failing to resolve. The onto-epistemic framework out of which this type of design injustice emerges is coloniality, highlighting a trans-locally experienced truth: our ontologies are our epistemologies. And our onto-epistemologies are our namologies–studies, perspectives, types, or ways of designing. If we instead embody an onto-epistemic framework of relationality, our design process becomes radically participatory. Radical Participatory Design (RPD) is meta-methadology that is participatory to the root or core. Using the models “designer as community member,” “community member as designer,” and “community member as facilitator,” RPD prioritizes relational, cultural, and spiritual knowledge, as well as lived experiential knowledge, over mainstream, institutional knowledge. Based on the experiential knowledge of employing radical participatory design over many years, we have induced a characteristic definition of RPD. Through an awareness of participation, we discuss the various benefits of RPD including genuine inclusion, true human-centeredness, moving beyond human-centeredness, embedded empathy, trauma-responsive design, and systemic action. We discuss the ethics of Radical Participatory design from both an equality and equity perspective. We offer ways of evaluating the success of the radically participatory design process. Lastly, we discuss the barriers and ways we have overcome them in our projects.