The article suggests the main aspects of implementation of the Smart City concept in Barcelona. It analyzes the documents of the Barcelona City Council on plans for the fulfillment of digital innovations and the success of integrating technologies into urban infrastructure aimed at improving people’s quality of life and rational resource management. An overview is provided on the connection between Smart City and sustainable development, emphasizing the importance of innovation in addressing urban challenges. The authors are focused on the analysis of technologies that have an impact on digital infrastructure, environmental sustainability, urban mobility and civic engagement. To assess the success of the implementation of the concept they present statistical data and reports on plans for execution provided by the Barcelona City Council. The main problems and obstacles faced by Barcelona in the implementation of the initiatives were identified. Nevertheless, the results of the study demonstrate significant progress of Barcelona in adaptation of the Smart City concept, which opens great prospects for further sustainable urban development. The experience of Barcelona can be shared with other cities contributing to the wider implementation of successful practices on a global scale. The article may be of interest to researchers and specialists engaged in the field of urban planning and sustainable development, including in Russian practice.