When it comes to developing efficient and environmentally friendly thermal management solutions for a wide range of high-tech applications, such as flexible electronics, energy storage, and environmental protection, thermally conductive papers have recently garnered much attention from researchers as a possible sustainable alternative to the current methods of electronic waste management. High-tech industries, including flexible electronics and sustainable energy, are increasingly utilizing cellulose, the most abundant renewable resource in nature. The distinctive structure of cellulose, with abundant hydroxyl groups and a mix of amorphous and crystalline domains, facilitates surface modification with various functional groups and enables transformation into different shapes and sizes. They subsequently improve the attributes of cellulose composites by encompassing their lightweight characteristics, optical transparency, specific surface area, and advantageous mechanical properties. From this context, this chapter sheds light on the thermal properties of cellulose and cellulose-based paper, a few perspectives on the challenges associated with the investigation of high-performance flexible thermally conductive paper, as well as recent methods for producing thermally conductive papers and their diverse high-tech applications.