Top experts in Living Lab research and practice from the European Network of Living Labs (ENoLL) have contributed to the Living Lab Methodology Handbook by sharing their knowledge on the most recent findings on the topic. This handbook introduces research background and serves as a practical guidance for researchers and practitioners on Living Lab methodologies, co-creation and user engagement. It also aims to inspire the reader with the lessons learned from thorough research together with practical experiences from real-life cases. The handbook is specifically focusing on the topical area of Internet of Things, and explains how the Living Lab approach can greatly support the research and development activities in that area. This handbook was initiated under the coordination and support action “User Engagement for Large Scale Pilots in the Internet of Things” (U4IoT) that provides online and offline toolkits, workshops and other forms of support to actively engage end-users and citizens in the pilot projects of European IoT Large-scale pilots programme. This project has received funding from the European Union’s Horizon 2020 research and innovation programme and the Swiss State Secretariat for Education, Research and Innovation under grant agreement No 732078.