Modern cities face numerous challenges due to the rapidly increasing strain on infrastructure. The implementation of “Smart City” technologies has emerged as a response to these challenges, utilizing information and communication technologies (ICT) to enhance the efficiency of urban operations, improve citizens’ quality of life, and promote sustainable development. This paper examines the key aspects and challenges of information security in Smart City systems, with a focus on the protection of data confidentiality, integrity, and availability. Special attention is given to the experiences of the United States and the European Union, which are leaders in the implementation of smart city technologies. The primary threats to Smart City systems include breaches of data confidentiality, integrity, and availability. The paper provides an analysis of protective methods against these threats, such as encryption, multi-factor authentication, and continuous system monitoring. Issues related to data availability are explored through the lens of vulnerabilities caused by cyberattacks. The presented approaches to addressing these challenges emphasize the need for continuous improvement of security measures. While the integration of cutting-edge technologies can significantly improve residents’ quality of life and the efficiency of urban services, it requires substantial investment and attention to cybersecurity concerns.