The Smart Cities Symposium Prague 2021 (the seventh annual conference) aims on exchange of ideas and best practices in the field of Smart cities. It covers whole range of topics, from the system point of view, through data mining and data processing, smart grids, up to multi-agent systems and other soft computing approaches. The Symposium aims to be a multidisciplinary forum for exchanging ideas and best practices in the field of Smart Cities not limited to theory but also including real world applications.