The Essential Guide to Co-design introduces readers to a collaborative design practice grounded in everyday knowledge, lived experience, and shared imagination. Written for designers, educators, students, and community members, the book offers practical resources for implementing co-design processes in real time. It moves deliberately across disciplinary and institutional boundaries, establishing a shared language and methodology for working with communities rather than for them. This book is organized into two interconnected parts. The first section introduces five chapters, each focused on a key phase of a co-design framework. The second section features eight interdisciplinary case studies that illustrate community-partnered co-design in action. Drawing from both academic and professional contexts, these examples highlight the flexibility and transferability of co-design across varied settings, scales, and forms of practice. At its core, this book is an open invitation to participate. Readers are invited to engage with the book’s accessible format, embedded activities, prompts, and colorful illustrations as they take part in shaping processes and places that matter most to them and their communities.