A multiscale modeling framework that bridges length scales from nanoscale to macroscale is employed to predict the interlaminar, and intralaminar enhancement in polymer matrix composite (PMC) laminates reinforced with carbon nanotube (CNT) architecture. Recently developed constitutive models, which are based on nanoscale information, are implemented using a high-fidelity micromechanics approach accounting for various material constituents and interphases. The microscale model is coupled with a finite element (FE) analysis, and the framework is used to investigate load transfer characteristics and fracture toughness in PMC laminates with CNTs dispersed in the matrix, and radially-grown on the fiber surface. It is shown that adding CNT reinforcement into the matrix or on fiber surface suggests a noteworthy increase in the transverse elastic modulus and interlaminar fracture toughness. The CNT growth height strongly influences the enhancement in fracture toughness. The developed multiscale methodology is versatile and can be used to investigate the structural response of PMCs with varying geometry and loading conditions. The model outputs can also help guide the design, development, and optimization of CNT-enhanced composites with improved mechanical properties.