ITU‐T's Technical Reports and Specifications 425 Cybersecurity, data protection and cyber resilience in smart sustainable cities Overview Smart and sustainable city deployments will be carried out by a diverse ecosystem of providers in innovative domains, involving state‐of‐the‐art technology, including critical and complex information and communication technology (ICT) implementations. These deployments can address different components and city systems, like intelligent transportation, connected health care, public safety and security, emergency services, smart grid and smart metering, intelligent buildings, etc. Increasing ICT complexity, hyper‐connectivity, namely through “Internet of Things” (IoT) environments, as well as the generation of significant amounts of data, will also mean increasing vulnerability, both to malicious attacks and unintentional incidents. By conceiving interconnected urban systems with cybersecurity and data protection in mind, city administrators will be able to ensure service continuity, safety and well‐being for citizens and businesses alike. This Technical Report details these cybersecurity and data protection considerations in smart and sustainable city developments. It will explore the requirements and challenges of creating a secure, reliable and resilient smart and sustainable city. It will also consider how administrations and the overall city ecosystems will need to provide innovative, resilient “smart” solutions that leverage digital information while protecting against malicious violations, unintentional damage and natural disasters.