Flexible ceramic fibers (FCFs) have emerged as a highly promising material for high-temperature applications, effectively combining the excellent thermal stability of ceramic materials with the robust mechanical properties of flexible fibers. This review provides a comprehensive overview of recent advances in multifunctional FCF devices, focusing on innovative methods across material selection, structural design, and fabrication techniques to enhance their functional properties. These improvements, i.e., mechanical strength, thermal conductivity, and oxidation resistance, make FCFs particularly suitable for a wide range of applications, including energy storage, sensing, and high-temperature filtration. Notably, advancements in fabrication techniques have enabled the creation of novel FCF devices for thermal insulation and high-temperature sensing, such as stretchable ceramic membranes and printable ceramic fiber papers. The review concludes by discussing the future potential of FCFs, especially in multifunctional applications in high-temperature environments, where they can serve as essential components of advanced technologies. This work highlights the versatility and potential of FCFs as a transformative material for next-generation high-temperature applications.