Flexible and free-standing electrospun nanofibres have been used as electrode materials in electrochemical energy storage systems due to their versatile properties, such as mechanical stability, superb electrical conductivity, and high functionality. In energy storage systems such as metal-ion, metal-air, and metal-sulphur batteries, electrospun nanofibres are vital for constructing flexible electrodes and substantially enhancing their electrochemical properties. The need for flexible batteries has increased with increasing demand for new products such as wearable and flexible devices, including smartwatches and flexible displays. Conventional batteries have several semirigid to rigid components that limit their expansion in the flexible device market. The creation of flexible and wearable batteries with greater mechanical flexibility, higher energy, and substantial power density is critical in meeting the demand for these new electronic items. The implementation of carbon and carbon-derived composites into flexible electrodes is required to realize this goal. It is essential to understand recent advances and the comprehensive foundation behind the synthesis and assembly of various flexible electrospun nanofibres. The design of nanofibres, including those comprising carbon, N-doped carbon, hierarchical, porous carbon, and metal/metal oxide carbon composites, will be explored. We will highlight the merits of electrospun carbon flexible electrodes by describing porosity, surface area, binder-free and free-standing electrode construction, cycling stability, and performance rate. Significant scientific progress has been achieved and logistical challenges have been met in promoting secondary battery usage; therefore, this review of flexible electrode materials will advance this easily used and sought-after technology. The challenges and prospects involved in the timely development of carbon nanofibre composite flexible electrodes and batteries will be addressed.