Composite laminates usually exhibit poor mechanical properties in the transverse direction. To overcome this issue, vertically aligned carbon nanotubes (VACNT) are employed perpendicular to the planer direction as a reinforcing element at the interfaces of the composite laminae. The present study investigates the influence of VACNT on the overall effective properties of antisymmetric angle–ply composite laminate, followed by the investigation of transverse deformation of the composite laminate subjected to a uniformly distributed load along thickness direction. This analysis is conducted via a two-step methodology. The initial phase involves the development of a numerical model for a thin layer of VACNT-reinforced material. This model is used to calculate the effective elastic constants by employing a three-dimensional micro-mechanics technique. The overall effective stiffness properties are calculated with and without applying VACNT reinforcement in the antisymmetric angle–ply composite laminate. The next step investigates the impact of different interfacial carbon nanotubes (CNT) on the transverse deformation of a simply supported composite plate by using a first-order shear deformation theory (FSDT)-based finite element formulation. For validation purposes, the transverse deformation is determined for graphite–epoxy antisymmetric angle–ply composite laminate without VACNT at the interfaces, and a good agreement is found when compared with the existing analytical solutions. Furthermore, the comparative study presented in the paper exhibits significant improvements in the transverse deformation of the VACNT-reinforced composite over the conventional graphite–epoxy antisymmetric angle–ply composite laminate.