Smart cities would depend on digital technologies that have the potential ahead where Blockchains would perform significantly. Blockchains has become popular because it offers adequate security than other solutions for a wide range of purpose. Blockchains can support the growth of smart cities due to their robust features like transparent, reliable, authenticate, and decentralized features. At present, big cities are utilizing sophisticated technologies with knowledge platforms to evaluate the quality of life of their residents. Society participation and dedication grow when humans are even more committed to responding with and being adaptable at some stage in their metropolis authorities and responding in an established way to personal problems. Big data, IoT, and Blockchain would accelerate and extend its government services, capacity, and even reduces costs and provides exciting opportunities like transportation services, exchanging services, healthcare services, etc. This study shows the reviews and importance of Blockchain in futuristic smart cities.