As a promising material in solar water evaporation technology, carbon-based nanocomposites have become one of the emerging materials over the last decade. The solar-driven applications using solar steam generation have been the gaining importance globally because of their increasing efficiency in photothermal conversion as well as their stability and environmental friendliness. This chapter reviews the conversion mechanisms with a focus on the unique properties and benefits of different carbon-based nanocomposites, such as graphene, carbon nanotubes, and carbon-based functional materials, as active enhancers of solar steam generation. It also reviews synthesis methods, structural characteristics, and surface modifications for enabling these materials to maximize the steam production with effective light absorption and heat concentration. Furthermore, the chapter looks at the incorporation of carbon-based nanocomposites with other metals and functional materials to form hybrid systems that further improve evaporation rates and purify water content. Research case studies and their experimental outcomes focus on realistic applications and performance parameters for these types of nanocomposites. The discussion also presents some challenges, such as scalability, cost-effectiveness, and chemical stability, providing a comprehensive overview of the current state and future directions of carbon-based nanocomposites in solar steam evaporation technology. Through experimental results in literature and actual mechanisms, this review chapter intends to guide researchers in developing more efficient, sustainable, and better economic solar-driven solutions for making effective and efficient steam production for different applications such as water desalination and treatment.