Abstract This paper presents a dynamic organic Rankine cycle waste heat recovery (ORC-WHR) Simulink® model and an engine model for heavy-duty diesel applications. The dynamic, physics-based ORC-WHR system model includes parallel evaporators, flow control valves, a turbine expander, a reservoir, and pumps. The evaporator model contains an enhanced pressure drop model, which calculates pressure drop for each working fluid phase via a linear relation to the axial location inside each phase. The ORC-WHR component models parameters are identified over large range of steady state and transient experimental data, which are collected from an ORC-WHR system on a 13 L heavy-duty diesel engine. The component models are integrated into an entire system model and the boundary conditions, inputs and outputs for the individual models are described. A GT-POWER® engine model and its transient validation is presented. The speed and torque profiles of a long-haul, constant speed variable-load heavy-duty cycle are processed through the engine model to produce the exhaust and recirculated exhaust gas transient conditions relevant for the ORC model. The ORC-WHR system then simulated over these highly transient engine conditions. Overall, this paper provides detailed guidelines for ORC-WHR system modeling, model calibration, and component models integration.