Smart city is one of the most exiting industries of 21st century. For this research paper the development of smart cities and its application is explored. The key results in this paper concerns what impact does industry 4.0 have on smart cities and with technological advancements what does the future look like for smart cities, how will they develop and how will they look in future. For this research the lastest research papers written on topic of smart cities were used, with industry 4.0 and research on integration of industry 4.0 into smart cities. The main result of this paper is to show the reader exactly what is smart city, what is industry 4.0 and how are they connected through modern cutting edge technologies.