The mechanical responses of low volume fraction Polyvinyl Alcohol (PVA)/Montmorillonite (MMT) nanocomposites were modeled using a hierarchical multiscale modeling method. Nanoscale Molecular Dynamics (MD) and mesoscale Finite Element Analysis (FEA) were used to bridge information regarding deformation mechanics within Polymer/Clay Nanocomposites (PCNs). MD computations of PVA/MMT interfaces were employed to calibrate a Traction-Separation (T-S) relation, which was then upscaled into a cohesive zone model (CZM) to model interfaces between PVA and MMT in a mesomechanical finite element framework. Virtual Composite Structure Generation (VCSG) was used to generate a quasirealistic Representative Volume Element (RVE), and explicit FEA was performed on the RVE to demonstrate delamination in the PCNs. The FEA featured an elasto-viscoelastic-viscoplastic Internal State Variable (ISV) model for the polymer host (PVA) and a CZM for the interfaces between MMT and PVA. The hierarchical length scale bridging methodology employed here for a polymer based composite has applications for many other material systems. Published by Elsevier Ltd.