This study presents highly stretchable and negative-Poisson-ratio porous metamaterials fabricated using uniaxial, biaxial, and triaxial hot-pressing strategies. The materials, composed of reduced graphene oxide (rGO) and polymer nanocomposites, exhibit exceptional stretchability, with some achieving up to 1200% strain. The uniaxially hot-pressed materials have folded porous structures and high stretchability, while biaxially and triaxially hot-pressed materials have reentrant porous structures and negative Poisson's ratios. These materials are used to create ultrabroad-range strain and pressure sensors, as well as smart thermal management and electromagnetic interference (EMI) shielding systems. The porous microstructures can be tuned via stretching, enabling reversible control of the materials' properties. The study highlights the versatility of these materials for applications in flexible electronics, thermal management, EMI shielding, and energy storage. The results demonstrate that the hot-pressing strategies can convert highly compressible aerogels with positive Poisson's ratios into highly stretchable metamaterials with near-zero or negative Poisson's ratios. The materials show high stretchability, elasticity, and durability, with the ability to reversibly tune their thermal insulation and EMI shielding properties. However, the electrical conductivity of the materials needs improvement for broader applications. The study provides a promising strategy for developing highly stretchable and negative-Poisson-ratio porous materials with potential applications in various fields.This study presents highly stretchable and negative-Poisson-ratio porous metamaterials fabricated using uniaxial, biaxial, and triaxial hot-pressing strategies. The materials, composed of reduced graphene oxide (rGO) and polymer nanocomposites, exhibit exceptional stretchability, with some achieving up to 1200% strain. The uniaxially hot-pressed materials have folded porous structures and high stretchability, while biaxially and triaxially hot-pressed materials have reentrant porous structures and negative Poisson's ratios. These materials are used to create ultrabroad-range strain and pressure sensors, as well as smart thermal management and electromagnetic interference (EMI) shielding systems. The porous microstructures can be tuned via stretching, enabling reversible control of the materials' properties. The study highlights the versatility of these materials for applications in flexible electronics, thermal management, EMI shielding, and energy storage. The results demonstrate that the hot-pressing strategies can convert highly compressible aerogels with positive Poisson's ratios into highly stretchable metamaterials with near-zero or negative Poisson's ratios. The materials show high stretchability, elasticity, and durability, with the ability to reversibly tune their thermal insulation and EMI shielding properties. However, the electrical conductivity of the materials needs improvement for broader applications. The study provides a promising strategy for developing highly stretchable and negative-Poisson-ratio porous materials with potential applications in various fields.