A novel strategy has been developed to create superelastic, hierarchical cellular-structured fibrous, isotropically bonded elastic reconstructed (FIBER) nanofibre-assembled cellular aerogels (NFAs). These materials combine electrospun nanofibres with fibrous freeze-shaping techniques to assemble elastic bulk aerogels with tunable densities and desirable shapes. The resulting FIBER NFAs exhibit densities of >0.12 mg cm⁻³, rapid recovery from deformation, efficient energy absorption, and multifunctionality in terms of thermal insulation, sound absorption, emulsion separation, and elasticity-responsive electric conduction. The successful synthesis of such materials provides new insights into the design and development of multifunctional NFAs for various applications. Ultra-low density materials are attractive for their wide range of applications in thermal insulation, catalyst supports, tissue engineering, battery electrodes, and acoustic, vibration, or shock energy damping. The ultralight regime below 10 mg cm⁻³ contains very few materials, including silica colloid aerogels, carbon nanotube aerogels, graphene monoliths, aerographite, and metal microlattices. These materials have cellular architectures and are synthesized by assembling various building blocks. The effective properties of ultralight cellular materials are defined by their cell geometry and the properties of the solid constituents. Electrospun nanofibres, which are at the forefront of advanced fibrous materials, combine robust mechanical strength, low density, fine flexibility, extremely high aspect ratio, and ease of scalable synthesis. These fibres hold great promise as an exceptional nanoscale building block for constructing macroscopic NFAs. However, the major problem associated with electrospun nanofibres is their anisotropic lamellar deposition character, which results in the assembly of close-packed membranes rather than bulk aerogels. The FIBER NFAs are created by combining the unique properties of organic nanofibres (elastic and easy to bond) with those of inorganic nanofibres (stiff and thermally stable) to yield hybrid fibrous networks with robust elasticity and stability. The synthesis involves the preparation of PAN/BA-a and SiO₂ nanofibre membranes, homogenization in a water/tert-butanol mixture, freeze-drying, and crosslinking treatment. The resulting FIBER NFAs exhibit a hierarchical cellular structure with open-cell geometry and high porosity, enabling superelasticity and multifunctionality. The FIBER NFAs demonstrate excellent mechanical properties, including superelasticity, high compressive strain, and fatigue resistance. They also exhibit multifunctionality in terms of thermal insulation, sound absorption, emulsion separation, and elasticity-responsive electric conduction. The FIBER NFAs can be scaled up to large volumes and have a wide range of applications, including as lightweight thermal insulation materials, pressure sensors, and environmental protection applications. The successful synthesis of FIBA novel strategy has been developed to create superelastic, hierarchical cellular-structured fibrous, isotropically bonded elastic reconstructed (FIBER) nanofibre-assembled cellular aerogels (NFAs). These materials combine electrospun nanofibres with fibrous freeze-shaping techniques to assemble elastic bulk aerogels with tunable densities and desirable shapes. The resulting FIBER NFAs exhibit densities of >0.12 mg cm⁻³, rapid recovery from deformation, efficient energy absorption, and multifunctionality in terms of thermal insulation, sound absorption, emulsion separation, and elasticity-responsive electric conduction. The successful synthesis of such materials provides new insights into the design and development of multifunctional NFAs for various applications. Ultra-low density materials are attractive for their wide range of applications in thermal insulation, catalyst supports, tissue engineering, battery electrodes, and acoustic, vibration, or shock energy damping. The ultralight regime below 10 mg cm⁻³ contains very few materials, including silica colloid aerogels, carbon nanotube aerogels, graphene monoliths, aerographite, and metal microlattices. These materials have cellular architectures and are synthesized by assembling various building blocks. The effective properties of ultralight cellular materials are defined by their cell geometry and the properties of the solid constituents. Electrospun nanofibres, which are at the forefront of advanced fibrous materials, combine robust mechanical strength, low density, fine flexibility, extremely high aspect ratio, and ease of scalable synthesis. These fibres hold great promise as an exceptional nanoscale building block for constructing macroscopic NFAs. However, the major problem associated with electrospun nanofibres is their anisotropic lamellar deposition character, which results in the assembly of close-packed membranes rather than bulk aerogels. The FIBER NFAs are created by combining the unique properties of organic nanofibres (elastic and easy to bond) with those of inorganic nanofibres (stiff and thermally stable) to yield hybrid fibrous networks with robust elasticity and stability. The synthesis involves the preparation of PAN/BA-a and SiO₂ nanofibre membranes, homogenization in a water/tert-butanol mixture, freeze-drying, and crosslinking treatment. The resulting FIBER NFAs exhibit a hierarchical cellular structure with open-cell geometry and high porosity, enabling superelasticity and multifunctionality. The FIBER NFAs demonstrate excellent mechanical properties, including superelasticity, high compressive strain, and fatigue resistance. They also exhibit multifunctionality in terms of thermal insulation, sound absorption, emulsion separation, and elasticity-responsive electric conduction. The FIBER NFAs can be scaled up to large volumes and have a wide range of applications, including as lightweight thermal insulation materials, pressure sensors, and environmental protection applications. The successful synthesis of FIB