The Digital Twin Munich is the digital heart of Munich’s smart city approach. The digital representation of the city addresses the challenges due to climate change, population growth and the need to become sustainable and resilient to maintain and improve the quality of life of its citizens. With its collaborative, cross-departmental approach, geodata, extensive specialized datasets and other data are integrated into a standardised and interoperable urban data infrastructure. The Digital Twin elevates digital participation. Interactive 3D models, extended reality (XR) applications and scenario-based simulations allow decision makers and citizens to explore alternatives, planning impacts, and drive the urban development processes. By cross-city collaborations and publicly funded projects, Munich’s Digital Twin contributes to national and European standardisation initiatives and replicable solutions for other city administrations.