Four pyrene derivatives were designed and synthesised in order to examine the effect of noncovalent sidewall functionalisation on the mechanical and electrical properties of multiwalled carbon nanotube buckypapers. High-density, slightly-aligned carbon nanotube buckypapers were prepared by a wet-laid process from a homogeneous dispersion of carbon nanotubes treated with a high-pressure homogeniser. The prepared pyrene derivatives were added to the carbon nanotube dispersion in order to induce the noncovalent sidewall functionalisation before the wet-laid process. The electrical conductivities of the buckypapers increased dramatically after the noncovalent sidewall functionalisation because of the enhanced charge transfer efficiency. Some of the functionalised carbon nanotube buckypapers also exhibited enhanced mechanical properties due to increased packing density and a tendency for the materials to align. All the fabrication procedures in this study were extraordinarily simple and economical to achieve effective structural materials for various applications.